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Web Content Accessibility Guidelines (WCAG) 2.2 Web Content Accessibility Guidelines (WCAG) 2.2 W3C Recommendation 05 October 2023 More details about this document This version: https://www.w3.org/TR/2023/REC-WCAG22-20231005/ Latest published version: https://www.w3.org/TR/WCAG22/ Latest editor's draft: https://w3c.github.io/wcag/guidelines/22/ History: https://www.w3.org/standards/history/WCAG22/ Commit history Implementation report: https://www.w3.org/WAI/WCAG22/implementation-report/ Previous Recommendation: https://www.w3.org/TR/WCAG21/ Editors: Alastair Campbell ( Nomensa ) Chuck Adams ( Oracle ) Rachael Bradley Montgomery ( Library of Congress ) Michael Cooper ( W3C ) Andrew Kirkpatrick ( Adobe ) Feedback: GitHub w3c/wcag ( pull requests , new issue , open issues ) Errata: Errata exists . See also translations . Copyright © 2020-2023 World Wide Web Consortium . W3C ® liability , trademark and document use rules apply. Abstract Web Content Accessibility Guidelines (WCAG) 2.2 covers a wide range of recommendations for making Web content more accessible.

Following these guidelines will make content more accessible to a wider range of people with disabilities, including accommodations for blindness and low vision, deafness and hearing loss, limited movement, speech disabilities, photosensitivity, and combinations of these, and some accommodation for learning disabilities and cognitive limitations; but will not address every user need for people with these disabilities. These guidelines address accessibility of web content on desktops, laptops, tablets, and mobile devices. Following these guidelines will also often make Web content more usable to users in general. WCAG 2.2 success criteria are written as testable statements that are not technology-specific. Guidance about satisfying the success criteria in specific technologies, as well as general information about interpreting the success criteria, is provided in separate documents. See Web Content Accessibility Guidelines (WCAG) Overview for an introduction and links to WCAG technical and educational material.

WCAG 2.2 extends Web Content Accessibility Guidelines 2.1 [ WCAG21 ], which was published as a W3C Recommendation June 2018. Content that conforms to WCAG 2.2 also conforms to WCAG 2.0 and WCAG 2.1. The WG intends that for policies requiring conformance to WCAG 2.0 or WCAG 2.1, WCAG 2.2 can provide an alternate means of conformance. The publication of WCAG 2.2 does not deprecate or supersede WCAG 2.0 or WCAG 2.1. While WCAG 2.0 and WCAG 2.1 remain W3C Recommendations, the W3C advises the use of WCAG 2.2 to maximize future applicability of accessibility efforts.

The W3C also encourages use of the most current version of WCAG when developing or updating Web accessibility policies. Status of This Document This section describes the status of this document at the time of its publication. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at https://www.w3.org/TR/. To comment, file an issue in the W3C WCAG GitHub repository . Although the proposed Success Criteria in this document reference issues tracking discussion, the Working Group requests that public comments be filed as new issues, one issue per discrete comment. It is free to create a GitHub account to file issues. If filing issues in GitHub is not feasible, send email to [email protected] ( comment archive ).

This document was published by the Accessibility Guidelines Working Group as a Recommendation using the Recommendation track . W3C recommends the wide deployment of this specification as a standard for the Web. A W3C Recommendation is a specification that, after extensive consensus-building, is endorsed by W3C and its Members, and has commitments from Working Group members to royalty-free licensing for implementations. This document was produced by a group operating under the 1 August 2017 W3C Patent Policy . W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent.

An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy . This document is governed by the 12 June 2023 W3C Process Document . Table of Contents Abstract Status of This Document Introduction Background on WCAG 2 WCAG 2 Layers of Guidance WCAG 2.2 Supporting Documents Requirements for WCAG 2.2 Comparison with WCAG 2.1 New Features in WCAG 2.2 Numbering in WCAG 2.2 Conformance to WCAG 2.2 Later Versions of Accessibility Guidelines 1. Perceivable 1.1 Text Alternatives 1.1.1 Non-text Content 1.2 Time-based Media 1.2.1 Audio-only and Video-only (Prerecorded) 1.2.2 Captions (Prerecorded) 1.2.3 Audio Description or Media Alternative (Prerecorded) 1.2.4 Captions (Live) 1.2.5 Audio Description (Prerecorded) 1.2.6 Sign Language (Prerecorded) 1.2.7 Extended Audio Description (Prerecorded) 1.2.8 Media Alternative (Prerecorded) 1.2.9 Audio-only (Live) 1.3 Adaptable 1.3.1 Info and Relationships 1.3.2 Meaningful Sequence 1.3.3 Sensory Characteristics 1.3.4 Orientation 1.3.5 Identify Input Purpose 1.3.6 Identify Purpose 1.4 Distinguishable 1.4.1 Use of Color 1.4.2 Audio Control 1.4.3 Contrast (Minimum) 1.4.4 Resize Text 1.4.5 Images of Text 1.4.6 Contrast (Enhanced) 1.4.7 Low or No Background Audio 1.4.8 Visual Presentation 1.4.9 Images of Text (No Exception) 1.4.10 Reflow 1.4.11 Non-text Contrast 1.4.12 Text Spacing 1.4.13 Content on Hover or Focus 2. Operable 2.1 Keyboard Accessible 2.1.1 Keyboard 2.1.2 No Keyboard Trap 2.1.3 Keyboard (No Exception) 2.1.4 Character Key Shortcuts 2.2 Enough Time 2.2.1 Timing Adjustable 2.2.2 Pause, Stop, Hide 2.2.3 No Timing 2.2.4 Interruptions 2.2.5 Re-authenticating 2.2.6 Timeouts 2.3 Seizures and Physical Reactions 2.3.1 Three Flashes or Below Threshold 2.3.2 Three Flashes 2.3.3 Animation from Interactions 2.4 Navigable 2.4.1 Bypass Blocks 2.4.2 Page Titled 2.4.3 Focus Order 2.4.4 Link Purpose (In Context) 2.4.5 Multiple Ways 2.4.6 Headings and Labels 2.4.7 Focus Visible 2.4.8 Location 2.4.9 Link Purpose (Link Only) 2.4.10 Section Headings 2.4.11 Focus Not Obscured (Minimum) 2.4.12 Focus Not Obscured (Enhanced) 2.4.13 Focus Appearance 2.5 Input Modalities 2.5.1 Pointer Gestures 2.5.2 Pointer Cancellation 2.5.3 Label in Name 2.5.4 Motion Actuation 2.5.5 Target Size (Enhanced) 2.5.6 Concurrent Input Mechanisms 2.5.7 Dragging Movements 2.5.8 Target Size (Minimum) 3.

Understandable 3.1 Readable 3.1.1 Language of Page 3.1.2 Language of Parts 3.1.3 Unusual Words 3.1.4 Abbreviations 3.1.5 Reading Level 3.1.6 Pronunciation 3.2 Predictable 3.2.1 On Focus 3.2.2 On Input 3.2.3 Consistent Navigation 3.2.4 Consistent Identification 3.2.5 Change on Request 3.2.6 Consistent Help 3.3 Input Assistance 3.3.1 Error Identification 3.3.2 Labels or Instructions 3.3.3 Error Suggestion 3.3.4 Error Prevention (Legal, Financial, Data) 3.3.5 Help 3.3.6 Error Prevention (All) 3.3.7 Redundant Entry 3.3.8 Accessible Authentication (Minimum) 3.3.9 Accessible Authentication (Enhanced) 4. Robust 4.1 Compatible 4.1.1 Parsing (Obsolete and removed) 4.1.2 Name, Role, Value 4.1.3 Status Messages 5. Conformance 5.1 Interpreting Normative Requirements 5.2 Conformance Requirements 5.2.1 Conformance Level 5.2.2 Full pages 5.2.3 Complete processes 5.2.4 Only Accessibility-Supported Ways of Using Technologies 5.2.5 Non-Interference 5.3 Conformance Claims (Optional) 5.3.1 Required Components of a Conformance Claim 5.3.2 Optional Components of a Conformance Claim 5.4 Statement of Partial Conformance - Third Party Content 5.5 Statement of Partial Conformance - Language 5.6 Privacy Considerations 5.7 Security Considerations 6. Glossary 7. Input Purposes for User Interface Components A.

Change Log B. Acknowledgments B.1 Participants of the AG WG active in the development of this document: B.2 Other previously active WCAG WG participants and other contributors to WCAG 2.0, WCAG 2.1, or supporting resources B.3 Enabling funders C. References C.1 Informative references Introduction This section is non-normative. Background on WCAG 2 Web Content Accessibility Guidelines (WCAG) 2.2 defines how to make Web content more accessible to people with disabilities. Accessibility involves a wide range of disabilities, including visual, auditory, physical, speech, cognitive, language, learning, and neurological disabilities.

Although these guidelines cover a wide range of issues, they are not able to address the needs of people with all types, degrees, and combinations of disability. These guidelines also make Web content more usable by older individuals with changing abilities due to aging and often improve usability for users in general. WCAG 2.2 is developed through the W3C process in cooperation with individuals and organizations around the world, with a goal of providing a shared standard for Web content accessibility that meets the needs of individuals, organizations, and governments internationally. WCAG 2.2 builds on WCAG 2.0 [ WCAG20 ] and WCAG 2.1 [ WCAG21 ], which in turn built on WCAG 1.0 [ WAI-WEBCONTENT ] and is designed to apply broadly to different Web technologies now and in the future, and to be testable with a combination of automated testing and human evaluation. For an introduction to WCAG, see the Web Content Accessibility Guidelines (WCAG) Overview . Significant challenges were encountered in defining additional criteria to address cognitive, language, and learning disabilities, including a short timeline for development as well as challenges in reaching consensus on testability, implementability, and international considerations of proposals.

Work will carry on in this area in future versions of WCAG. We encourage authors to refer to our supplemental guidance on improving inclusion for people with disabilities, including learning and cognitive disabilities, people with low-vision, and more . Web accessibility depends not only on accessible content but also on accessible Web browsers and other user agents. Authoring tools also have an important role in Web accessibility. For an overview of how these components of Web development and interaction work together, see: Essential Components of Web Accessibility User Agent Accessibility Guidelines (UAAG) Overview Authoring Tool Accessibility Guidelines (ATAG) Overview Where this document refers to WCAG 2 it is intended to mean any and all versions of WCAG that start with 2.

WCAG 2 Layers of Guidance The individuals and organizations that use WCAG vary widely and include Web designers and developers, policy makers, purchasing agents, teachers, and students. In order to meet the varying needs of this audience, several layers of guidance are provided including overall principles , general guidelines , testable success criteria and a rich collection of sufficient techniques , advisory techniques , and documented common failures with examples, resource links and code. Principles - At the top are four principles that provide the foundation for Web accessibility: perceivable, operable, understandable, and robust . See also Understanding the Four Principles of Accessibility . Guidelines - Under the principles are guidelines.

The 13 guidelines provide the basic goals that authors should work toward in order to make content more accessible to users with different disabilities. The guidelines are not testable, but provide the framework and overall objectives to help authors understand the success criteria and better implement the techniques. Success Criteria - For each guideline, testable success criteria are provided to allow WCAG 2.2 to be used where requirements and conformance testing are necessary such as in design specification, purchasing, regulation, and contractual agreements. In order to meet the needs of different groups and different situations, three levels of conformance are defined: A (lowest), AA, and AAA (highest). Additional information on WCAG levels can be found in Understanding Levels of Conformance .

Sufficient and Advisory Techniques - For each of the guidelines and success criteria in the WCAG 2.2 document itself, the working group has also documented a wide variety of techniques . The techniques are informative and fall into two categories: those that are sufficient for meeting the success criteria and those that are advisory . The advisory techniques go beyond what is required by the individual success criteria and allow authors to better address the guidelines. Some advisory techniques address accessibility barriers that are not covered by the testable success criteria. Where common failures are known, these are also documented.

See also Sufficient and Advisory Techniques in Understanding WCAG 2.2 . All of these layers of guidance (principles, guidelines, success criteria, and sufficient and advisory techniques) work together to provide guidance on how to make content more accessible. Authors are encouraged to view and apply all layers that they are able to, including the advisory techniques, in order to best address the needs of the widest possible range of users. Note that even content that conforms at the highest level (AAA) will not be accessible to individuals with all types, degrees, or combinations of disability, particularly in the cognitive, language, and learning areas. Authors are encouraged to consider the full range of techniques, including the advisory techniques, Making Content Usable for People with Cognitive and Learning Disabilities , as well as to seek relevant advice about current best practice to ensure that Web content is accessible, as far as possible, to this community.

Metadata may assist users in finding content most suitable for their needs. WCAG 2.2 Supporting Documents The WCAG 2.2 document is designed to meet the needs of those who need a stable, referenceable technical standard. Other documents, called supporting documents, are based on the WCAG 2.2 document and address other important purposes, including the ability to be updated to describe how WCAG would be applied with new technologies. Supporting documents include: How to Meet WCAG 2.2 - A customizable quick reference to WCAG 2.2 that includes all of the guidelines, success criteria, and techniques for authors to use as they are developing and evaluating Web content. This includes content from WCAG 2.0, 2.1 2.2 and can be filtered in many ways to help authors focus on relevant content.

Understanding WCAG 2.2 - A guide to understanding and implementing WCAG 2.2. There is a short "Understanding" document for each guideline and success criterion in WCAG 2.2 as well as key topics. Techniques for WCAG 2.2 - A collection of techniques and common failures, each in a separate document that includes a description, examples, code and tests. The WCAG 2 Documents - A brief introduction to the WCAG 2 supporting documents and supplemental guidance. What's New in WCAG 2.2 introduces the new success criteria with persona quotes that illustrate the accessibility issues.

See Web Content Accessibility Guidelines (WCAG) Overview for a description of the WCAG 2.2 supporting material, including education resources related to WCAG 2. Additional resources covering topics such as the business case for Web accessibility, planning implementation to improve the accessibility of Web sites, and accessibility policies are listed in WAI Resources . Requirements for WCAG 2.2 WCAG 2.2 meets a set of requirements for WCAG 2.2 which, in turn, inherit requirements from previous WCAG 2 versions. Requirements structure the overall framework of guidelines and ensure backwards compatibility. The Working Group also used a less formal set of acceptance criteria for success criteria, to help ensure success criteria are similar in style and quality to those in WCAG 2.0. These requirements constrained what could be included in WCAG 2.2.

This constraint was important to preserve its nature as a dot-release of WCAG 2. Comparison with WCAG 2.1 WCAG 2.2 was initiated with the goal to continue the work of WCAG 2.1: Improving accessibility guidance for three major groups: users with cognitive or learning disabilities, users with low vision, and users with disabilities on mobile devices. Many ways to meet these needs were proposed and evaluated, and a set of these were refined by the Working Group. Structural requirements inherited from WCAG 2.0, clarity and impact of proposals, and timeline led to the final set of success criteria included in this version. The Working Group considers that WCAG 2.2 incrementally advances web content accessibility guidance for all these areas, but underscores that not all user needs are met by these guidelines.

WCAG 2.2 builds on and is backwards compatible with WCAG 2.1, meaning web pages that conform to WCAG 2.2 are at least as accessible as pages that conform to WCAG 2.1. Requirements have been added that build on 2.1 and 2.0. WCAG 2.2 has removed one success criterion, 4.1.1 Parsing . Authors that are required by policy to conform with WCAG 2.0 or 2.1 will be able to update content to WCAG 2.2, but may need to continue to test and report 4.1.1. Authors following more than one version of the guidelines should be aware of the following additions. New Features in WCAG 2.2 WCAG 2.2 extends WCAG 2.1 by adding new success criteria, definitions to support them, and guidelines to organize the additions. This additive approach helps to make it clear that sites which conform to WCAG 2.2 also conform to WCAG 2.1.

The Accessibility Guidelines Working Group recommends that sites adopt WCAG 2.2 as their new conformance target, even if formal obligations mention previous versions, to provide improved accessibility and to anticipate future policy changes. The following success criteria are new in WCAG 2.2: 2.4.11 Focus Not Obscured (Minimum) (AA) 2.4.12 Focus Not Obscured (Enhanced) (AAA) 2.4.13 Focus Appearance (AAA) 2.5.7 Dragging Movements (AA) 2.5.8 Target Size (Minimum) (AA) 3.2.6 Consistent Help (A) 3.3.7 Redundant Entry (A) 3.3.8 Accessible Authentication (Minimum) (AA) 3.3.9 Accessible Authentication (Enhanced) (AAA) The new success criteria may reference new terms that have also been added to the glossary and form part of the normative requirements of the success criteria. WCAG 2.2 also introduces new sections detailing aspects of the specification which may impact privacy and security . Numbering in WCAG 2.2 In order to avoid confusion for implementers for whom backwards compatibility to WCAG 2 versions is important, new success criteria in WCAG 2.2 have been appended to the end of the set of success criteria within their guideline. This avoids the need to change the section number of success criteria from WCAG 2, which would be caused by inserting new success criteria between existing success criteria in the guideline, but it means success criteria in each guideline are no longer grouped by conformance level.

The order of success criteria within each guideline does not imply information about conformance level; only the conformance level indicator (A / AA / AAA) on the success criterion itself indicates this. The WCAG 2.2 Quick Reference will provide a way to view success criteria grouped by conformance level, along with many other filter and sort options. Conformance to WCAG 2.2 WCAG 2.2 uses the same conformance model as WCAG 2.0. It is intended that sites that conform to WCAG 2.2 also conform to WCAG 2.0 and WCAG 2.1, which means they meet the requirements of any policies that reference WCAG 2.0 or WCAG 2.1, while also better meeting the needs of users on the current Web. Later Versions of Accessibility Guidelines In parallel with WCAG 2.2, the Accessibility Guidelines Working Group is developing another major version of accessibility guidelines.

The result of this work is expected to be a more substantial restructuring of web accessibility guidance than would be realistic for dot-releases of WCAG 2. The work follows a research-focused, user-centered design methodology to produce the most effective and flexible outcome, including the roles of content authoring, user agent support, and authoring tool support. This is a multi-year effort, so WCAG 2.2 is needed as an interim measure to provide updated web accessibility guidance to reflect changes on the web since the publication of WCAG 2.0. The Working Group might also develop additional interim versions, continuing with WCAG 2.2, on a similar short timeline to provide additional support while the major version is completed. 1.

Perceivable Information and user interface components must be presentable to users in ways they can perceive. Guideline 1.1 Text Alternatives Understanding Text Alternatives | How to Meet Text Alternatives Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language. Success Criterion 1.1.1 Non-text Content Understanding Non-text Content | How to Meet Non-text Content (Level A) All non-text content that is presented to the user has a text alternative that serves the equivalent purpose, except for the situations listed below. Controls, Input If non-text content is a control or accepts user input, then it has a name that describes its purpose. (Refer to Success Criterion 4.1.2 for additional requirements for controls and content that accepts user input.) Time-Based Media If non-text content is time-based media, then text alternatives at least provide descriptive identification of the non-text content.

(Refer to Guideline 1.2 for additional requirements for media.) Test If non-text content is a test or exercise that would be invalid if presented in text , then text alternatives at least provide descriptive identification of the non-text content. Sensory If non-text content is primarily intended to create a specific sensory experience , then text alternatives at least provide descriptive identification of the non-text content. CAPTCHA If the purpose of non-text content is to confirm that content is being accessed by a person rather than a computer, then text alternatives that identify and describe the purpose of the non-text content are provided, and alternative forms of CAPTCHA using output modes for different types of sensory perception are provided to accommodate different disabilities. Decoration, Formatting, Invisible If non-text content is pure decoration , is used only for visual formatting, or is not presented to users, then it is implemented in a way that it can be ignored by assistive technology . Guideline 1.2 Time-based Media Understanding Time-based Media | How to Meet Time-based Media Provide alternatives for time-based media.

Success Criterion 1.2.1 Audio-only and Video-only (Prerecorded) Understanding Audio-only and Video-only (Prerecorded) | How to Meet Audio-only and Video-only (Prerecorded) (Level A) For prerecorded audio-only and prerecorded video-only media, the following are true, except when the audio or video is a media alternative for text and is clearly labeled as such: Prerecorded Audio-only An alternative for time-based media is provided that presents equivalent information for prerecorded audio-only content. Prerecorded Video-only Either an alternative for time-based media or an audio track is provided that presents equivalent information for prerecorded video-only content. Success Criterion 1.2.2 Captions (Prerecorded) Understanding Captions (Prerecorded) | How to Meet Captions (Prerecorded) (Level A) Captions are provided for all prerecorded audio content in synchronized media , except when the media is a media alternative for text and is clearly labeled as such. Success Criterion 1.2.3 Audio Description or Media Alternative (Prerecorded) Understanding Audio Description or Media Alternative (Prerecorded) | How to Meet Audio Description or Media Alternative (Prerecorded) (Level A) An alternative for time-based media or audio description of the prerecorded video content is provided for synchronized media , except when the media is a media alternative for text and is clearly labeled as such. Success Criterion 1.2.4 Captions (Live) Understanding Captions (Live) | How to Meet Captions (Live) (Level AA) Captions are provided for all live audio content in synchronized media .

Success Criterion 1.2.5 Audio Description (Prerecorded) Understanding Audio Description (Prerecorded) | How to Meet Audio Description (Prerecorded) (Level AA) Audio description is provided for all prerecorded video content in synchronized media . Success Criterion 1.2.6 Sign Language (Prerecorded) Understanding Sign Language (Prerecorded) | How to Meet Sign Language (Prerecorded) (Level AAA) Sign language interpretation is provided for all prerecorded audio content in synchronized media . Success Criterion 1.2.7 Extended Audio Description (Prerecorded) Understanding Extended Audio Description (Prerecorded) | How to Meet Extended Audio Description (Prerecorded) (Level AAA) Where pauses in foreground audio are insufficient to allow audio descriptions to convey the sense of the video, extended audio description is provided for all prerecorded video content in synchronized media . Success Criterion 1.2.8 Media Alternative (Prerecorded) Understanding Media Alternative (Prerecorded) | How to Meet Media Alternative (Prerecorded) (Level AAA) An alternative for time-based media is provided for all prerecorded synchronized media and for all prerecorded video-only media. Success Criterion 1.2.9 Audio-only (Live) Understanding Audio-only (Live) | How to Meet Audio-only (Live) (Level AAA) An alternative for time-based media that presents equivalent information for live audio-only content is provided.

Guideline 1.3 Adaptable Understanding Adaptable | How to Meet Adaptable Create content that can be presented in different ways (for example simpler layout) without losing information or structure. Success Criterion 1.3.1 Info and Relationships Understanding Info and Relationships | How to Meet Info and Relationships (Level A) Information, structure , and relationships conveyed through presentation can be programmatically determined or are available in text. Success Criterion 1.3.2 Meaningful Sequence Understanding Meaningful Sequence | How to Meet Meaningful Sequence (Level A) When the sequence in which content is presented affects its meaning, a correct reading sequence can be programmatically determined . Success Criterion 1.3.3 Sensory Characteristics Understanding Sensory Characteristics | How to Meet Sensory Characteristics (Level A) Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, color, size, visual location, orientation, or sound. Note For requirements related to color, refer to Guideline 1.4 .

Success Criterion 1.3.4 Orientation Understanding Orientation | How to Meet Orientation (Level AA) Content does not restrict its view and operation to a single display orientation, such as portrait or landscape, unless a specific display orientation is essential . Note Examples where a particular display orientation may be essential are a bank check, a piano application, slides for a projector or television, or virtual reality content where content is not necessarily restricted to landscape or portrait display orientation. Success Criterion 1.3.5 Identify Input Purpose Understanding Identify Input Purpose | How to Meet Identify Input Purpose (Level AA) The purpose of each input field collecting information about the user can be programmatically determined when: The input field serves a purpose identified in the Input Purposes for user interface components section ; and The content is implemented using technologies with support for identifying the expected meaning for form input data. Success Criterion 1.3.6 Identify Purpose Understanding Identify Purpose | How to Meet Identify Purpose (Level AAA) In content implemented using markup languages, the purpose of user interface components , icons, and regions can be programmatically determined . Guideline 1.4 Distinguishable Understanding Distinguishable | How to Meet Distinguishable Make it easier for users to see and hear content including separating foreground from background.

Success Criterion 1.4.1 Use of Color Understanding Use of Color | How to Meet Use of Color (Level A) Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. Note This success criterion addresses color perception specifically. Other forms of perception are covered in Guideline 1.3 including programmatic access to color and other visual presentation coding. Success Criterion 1.4.2 Audio Control Understanding Audio Control | How to Meet Audio Control (Level A) If any audio on a Web page plays automatically for more than 3 seconds, either a mechanism is available to pause or stop the audio, or a mechanism is available to control audio volume independently from the overall system volume level. Note Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether or not it is used to meet other success criteria) must meet this success criterion.

See Conformance Requirement 5: Non-Interference . Success Criterion 1.4.3 Contrast (Minimum) Understanding Contrast (Minimum) | How to Meet Contrast (Minimum) (Level AA) The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for the following: Large Text Large-scale text and images of large-scale text have a contrast ratio of at least 3:1; Incidental Text or images of text that are part of an inactive user interface component , that are pure decoration , that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement. Logotypes Text that is part of a logo or brand name has no contrast requirement. Success Criterion 1.4.4 Resize Text Understanding Resize Text | How to Meet Resize Text (Level AA) Except for captions and images of text , text can be resized without assistive technology up to 200 percent without loss of content or functionality. Success Criterion 1.4.5 Images of Text Understanding Images of Text | How to Meet Images of Text (Level AA) If the technologies being used can achieve the visual presentation, text is used to convey information rather than images of text except for the following: Customizable The image of text can be visually customized to the user's requirements; Essential A particular presentation of text is essential to the information being conveyed.

Note Logotypes (text that is part of a logo or brand name) are considered essential. Success Criterion 1.4.6 Contrast (Enhanced) Understanding Contrast (Enhanced) | How to Meet Contrast (Enhanced) (Level AAA) The visual presentation of text and images of text has a contrast ratio of at least 7:1, except for the following: Large Text Large-scale text and images of large-scale text have a contrast ratio of at least 4.5:1; Incidental Text or images of text that are part of an inactive user interface component , that are pure decoration , that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement. Logotypes Text that is part of a logo or brand name has no contrast requirement. Success Criterion 1.4.7 Low or No Background Audio Understanding Low or No Background Audio | How to Meet Low or No Background Audio (Level AAA) For prerecorded audio-only content that (1) contains primarily speech in the foreground, (2) is not an audio CAPTCHA or audio logo, and (3) is not vocalization intended to be primarily musical expression such as singing or rapping, at least one of the following is true: No Background The audio does not contain background sounds. Turn Off The background sounds can be turned off.

20 dB The background sounds are at least 20 decibels lower than the foreground speech content, with the exception of occasional sounds that last for only one or two seconds. Note Per the definition of "decibel," background sound that meets this requirement will be approximately four times quieter than the foreground speech content. Success Criterion 1.4.8 Visual Presentation Understanding Visual Presentation | How to Meet Visual Presentation (Level AAA) For the visual presentation of blocks of text , a mechanism is available to achieve the following: Foreground and background colors can be selected by the user. Width is no more than 80 characters or glyphs (40 if CJK). Text is not justified (aligned to both the left and the right margins).

Line spacing (leading) is at least space-and-a-half within paragraphs, and paragraph spacing is at least 1.5 times larger than the line spacing. Text can be resized without assistive technology up to 200 percent in a way that does not require the user to scroll horizontally to read a line of text on a full-screen window . Note 1 Content is not required to use these values. The requirement is that a mechanism is available for users to change these presentation aspects. The mechanism can be provided by the browser or other user agent.

Content is not required to provide the mechanism. Note 2 Writing systems for some languages use different presentation aspects to improve readability and legibility. If a presentation aspect in this success criterion is not used in a writing system, content in that writing system does not need to use that presentation setting and can conform without it. Authors are encouraged to follow guidance for improving readability and legibility of text in their writing system. Success Criterion 1.4.9 Images of Text (No Exception) Understanding Images of Text (No Exception) | How to Meet Images of Text (No Exception) (Level AAA) Images of text are only used for pure decoration or where a particular presentation of text is essential to the information being conveyed.

Note Logotypes (text that is part of a logo or brand name) are considered essential. Success Criterion 1.4.10 Reflow Understanding Reflow | How to Meet Reflow (Level AA) Content can be presented without loss of information or functionality, and without requiring scrolling in two dimensions for: Vertical scrolling content at a width equivalent to 320 CSS pixels ; Horizontal scrolling content at a height equivalent to 256 CSS pixels . Except for parts of the content which require two-dimensional layout for usage or meaning. Note 1 320 CSS pixels is equivalent to a starting viewport width of 1280 CSS pixels wide at 400% zoom. For web content which is designed to scroll horizontally (e.g., with vertical text), 256 CSS pixels is equivalent to a starting viewport height of 1024 CSS pixels at 400% zoom.

Note 2 Examples of content which requires two-dimensional layout are images required for understanding (such as maps and diagrams), video, games, presentations, data tables (not individual cells), and interfaces where it is necessary to keep toolbars in view while manipulating content. It is acceptable to provide two-dimensional scrolling for such parts of the content. Success Criterion 1.4.11 Non-text Contrast Understanding Non-text Contrast | How to Meet Non-text Contrast (Level AA) The visual presentation of the following have a contrast ratio of at least 3:1 against adjacent color(s): User Interface Components Visual information required to identify user interface components and states , except for inactive components or where the appearance of the component is determined by the user agent and not modified by the author; Graphical Objects Parts of graphics required to understand the content, except when a particular presentation of graphics is essential to the information being conveyed. Success Criterion 1.4.12 Text Spacing Understanding Text Spacing | How to Meet Text Spacing (Level AA) In content implemented using markup languages that support the following text style properties , no loss of content or functionality occurs by setting all of the following and by changing no other style property: Line height (line spacing) to at least 1.5 times the font size; Spacing following paragraphs to at least 2 times the font size; Letter spacing (tracking) to at least 0.12 times the font size; Word spacing to at least 0.16 times the font size. Exception: Human languages and scripts that do not make use of one or more of these text style properties in written text can conform using only the properties that exist for that combination of language and script.

Note 1 Content is not required to use these text spacing values. The requirement is to ensure that when a user overrides the authored text spacing, content or functionality is not lost. Note 2 Writing systems for some languages use different text spacing settings, such as paragraph start indent. Authors are encouraged to follow locally available guidance for improving readability and legibility of text in their writing system. Success Criterion 1.4.13 Content on Hover or Focus Understanding Content on Hover or Focus | How to Meet Content on Hover or Focus (Level AA) Where receiving and then removing pointer hover or keyboard focus triggers additional content to become visible and then hidden, the following are true: Dismissible A mechanism is available to dismiss the additional content without moving pointer hover or keyboard focus, unless the additional content communicates an input error or does not obscure or replace other content; Hoverable If pointer hover can trigger the additional content, then the pointer can be moved over the additional content without the additional content disappearing; Persistent The additional content remains visible until the hover or focus trigger is removed, the user dismisses it, or its information is no longer valid.

Exception: The visual presentation of the additional content is controlled by the user agent and is not modified by the author. Note 1 Examples of additional content controlled by the user agent include browser tooltips created through use of the HTML title attribute [ HTML ]. Note 2 Custom tooltips, sub-menus, and other nonmodal popups that display on hover and focus are examples of additional content covered by this criterion. Note 3 This criterion applies to content that appears in addition to the triggering component itself. Since hidden components that are made visible on keyboard focus (such as links used to skip to another part of a page) do not present additional content they are not covered by this criterion.

2. Operable User interface components and navigation must be operable. Guideline 2.1 Keyboard Accessible Understanding Keyboard Accessible | How to Meet Keyboard Accessible Make all functionality available from a keyboard. Success Criterion 2.1.1 Keyboard Understanding Keyboard | How to Meet Keyboard (Level A) All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints. Note 1 This exception relates to the underlying function, not the input technique.

For example, if using handwriting to enter text, the input technique (handwriting) requires path-dependent input but the underlying function (text input) does not. Note 2 This does not forbid and should not discourage providing mouse input or other input methods in addition to keyboard operation. Success Criterion 2.1.2 No Keyboard Trap Understanding No Keyboard Trap | How to Meet No Keyboard Trap (Level A) If keyboard focus can be moved to a component of the page using a keyboard interface , then focus can be moved away from that component using only a keyboard interface, and, if it requires more than unmodified arrow or tab keys or other standard exit methods, the user is advised of the method for moving focus away. Note Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference .

Success Criterion 2.1.3 Keyboard (No Exception) Understanding Keyboard (No Exception) | How to Meet Keyboard (No Exception) (Level AAA) All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes. Success Criterion 2.1.4 Character Key Shortcuts Understanding Character Key Shortcuts | How to Meet Character Key Shortcuts (Level A) If a keyboard shortcut is implemented in content using only letter (including upper- and lower-case letters), punctuation, number, or symbol characters, then at least one of the following is true: Turn off A mechanism is available to turn the shortcut off; Remap A mechanism is available to remap the shortcut to include one or more non-printable keyboard keys (e.g., Ctrl, Alt); Active only on focus The keyboard shortcut for a user interface component is only active when that component has focus. Guideline 2.2 Enough Time Understanding Enough Time | How to Meet Enough Time Provide users enough time to read and use content. Success Criterion 2.2.1 Timing Adjustable Understanding Timing Adjustable | How to Meet Timing Adjustable (Level A) For each time limit that is set by the content, at least one of the following is true: Turn off The user is allowed to turn off the time limit before encountering it; or Adjust The user is allowed to adjust the time limit before encountering it over a wide range that is at least ten times the length of the default setting; or Extend The user is warned before time expires and given at least 20 seconds to extend the time limit with a simple action (for example, "press the space bar"), and the user is allowed to extend the time limit at least ten times; or Real-time Exception The time limit is a required part of a real-time event (for example, an auction), and no alternative to the time limit is possible; or Essential Exception The time limit is essential and extending it would invalidate the activity; or 20 Hour Exception The time limit is longer than 20 hours. Note This success criterion helps ensure that users can complete tasks without unexpected changes in content or context that are a result of a time limit.

This success criterion should be considered in conjunction with Success Criterion 3.2.1 , which puts limits on changes of content or context as a result of user action. Success Criterion 2.2.2 Pause, Stop, Hide Understanding Pause, Stop, Hide | How to Meet Pause, Stop, Hide (Level A) For moving, blinking , scrolling, or auto-updating information, all of the following are true: Moving, blinking, scrolling For any moving, blinking or scrolling information that (1) starts automatically, (2) lasts more than five seconds, and (3) is presented in parallel with other content, there is a mechanism for the user to pause , stop, or hide it unless the movement, blinking, or scrolling is part of an activity where it is essential ; and Auto-updating For any auto-updating information that (1) starts automatically and (2) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it or to control the frequency of the update unless the auto-updating is part of an activity where it is essential. Note 1 For requirements related to flickering or flashing content, refer to Guideline 2.3 . Note 2 Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference .

Note 3 Content that is updated periodically by software or that is streamed to the user agent is not required to preserve or present information that is generated or received between the initiation of the pause and resuming presentation, as this may not be technically possible, and in many situations could be misleading to do so. Note 4 An animation that occurs as part of a preload phase or similar situation can be considered essential if interaction cannot occur during that phase for all users and if not indicating progress could confuse users or cause them to think that content was frozen or broken. Success Criterion 2.2.3 No Timing Understanding No Timing | How to Meet No Timing (Level AAA) Timing is not an essential part of the event or activity presented by the content, except for non-interactive synchronized media and real-time events . Success Criterion 2.2.4 Interruptions Understanding Interruptions | How to Meet Interruptions (Level AAA) Interruptions can be postponed or suppressed by the user, except interruptions involving an emergency . Success Criterion 2.2.5 Re-authenticating Understanding Re-authenticating | How to Meet Re-authenticating (Level AAA) When an authenticated session expires, the user can continue the activity without loss of data after re-authenticating.

Success Criterion 2.2.6 Timeouts Understanding Timeouts | How to Meet Timeouts (Level AAA) Users are warned of the duration of any user inactivity that could cause data loss, unless the data is preserved for more than 20 hours when the user does not take any actions. Note Privacy regulations may require explicit user consent before user identification has been authenticated and before user data is preserved. In cases where the user is a minor, explicit consent may not be solicited in most jurisdictions, countries or regions. Consultation with privacy professionals and legal counsel is advised when considering data preservation as an approach to satisfy this success criterion. Guideline 2.3 Seizures and Physical Reactions Understanding Seizures and Physical Reactions | How to Meet Seizures and Physical Reactions Do not design content in a way that is known to cause seizures or physical reactions.

Success Criterion 2.3.1 Three Flashes or Below Threshold Understanding Three Flashes or Below Threshold | How to Meet Three Flashes or Below Threshold (Level A) Web pages do not contain anything that flashes more than three times in any one second period, or the flash is below the general flash and red flash thresholds . Note Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference . Success Criterion 2.3.2 Three Flashes Understanding Three Flashes | How to Meet Three Flashes (Level AAA) Web pages do not contain anything that flashes more than three times in any one second period. Success Criterion 2.3.3 Animation from Interactions Understanding Animation from Interactions | How to Meet Animation from Interactions (Level AAA) Motion animation triggered by interaction can be disabled, unless the animation is essential to the functionality or the information being conveyed.

Guideline 2.4 Navigable Understanding Navigable | How to Meet Navigable Provide ways to help users navigate, find content, and determine where they are. Success Criterion 2.4.1 Bypass Blocks Understanding Bypass Blocks | How to Meet Bypass Blocks (Level A) A mechanism is available to bypass blocks of content that are repeated on multiple Web pages . Success Criterion 2.4.2 Page Titled Understanding Page Titled | How to Meet Page Titled (Level A) Web pages have titles that describe topic or purpose. Success Criterion 2.4.3 Focus Order Understanding Focus Order | How to Meet Focus Order (Level A) If a Web page can be navigated sequentially and the navigation sequences affect meaning or operation, focusable components receive focus in an order that preserves meaning and operability. Success Criterion 2.4.4 Link Purpose (In Context) Understanding Link Purpose (In Context) | How to Meet Link Purpose (In Context) (Level A) The purpose of each link can be determined from the link text alone or from the link text together with its programmatically determined link context , except where the purpose of the link would be ambiguous to users in general .

Success Criterion 2.4.5 Multiple Ways Understanding Multiple Ways | How to Meet Multiple Ways (Level AA) More than one way is available to locate a Web page within a set of Web pages except where the Web Page is the result of, or a step in, a process . Success Criterion 2.4.6 Headings and Labels Understanding Headings and Labels | How to Meet Headings and Labels (Level AA) Headings and labels describe topic or purpose. Success Criterion 2.4.7 Focus Visible Understanding Focus Visible | How to Meet Focus Visible (Level AA) Any keyboard operable user interface has a mode of operation where the keyboard focus indicator is visible. Success Criterion 2.4.8 Location Understanding Location | How to Meet Location (Level AAA) Information about the user's location within a set of Web pages is available. Success Criterion 2.4.9 Link Purpose (Link Only) Understanding Link Purpose (Link Only) | How to Meet Link Purpose (Link Only) (Level AAA) A mechanism is available to allow the purpose of each link to be identified from link text alone, except where the purpose of the link would be ambiguous to users in general .

Success Criterion 2.4.10 Section Headings Understanding Section Headings | How to Meet Section Headings (Level AAA) Section headings are used to organize the content. Note 1 "Heading" is used in its general sense and includes titles and other ways to add a heading to different types of content. Note 2 This success criterion covers sections within writing, not user interface components . User interface components are covered under Success Criterion 4.1.2 . Success Criterion 2.4.11 Focus Not Obscured (Minimum) Understanding Focus Not Obscured (Minimum) | How to Meet Focus Not Obscured (Minimum) (Level AA) [New] When a user interface component receives keyboard focus, the component is not entirely hidden due to author-created content.

Note 1 Where content in a configurable interface can be repositioned by the user, then only the initial positions of user-movable content are considered for testing and conformance of this Success Criterion. Note 2 Content opened by the user may obscure the component receiving focus. If the user can reveal the focused component without advancing the keyboard focus, the component with focus is not considered hidden due to author-created content. Success Criterion 2.4.12 Focus Not Obscured (Enhanced) Understanding Focus Not Obscured (Enhanced) | How to Meet Focus Not Obscured (Enhanced) (Level AAA) [New] When a user interface component receives keyboard focus, no part of the component is hidden by author-created content. Success Criterion 2.4.13 Focus Appearance Understanding Focus Appearance | How to Meet Focus Appearance (Level AAA) [New] When the keyboard focus indicator is visible, an area of the focus indicator meets all the following: is at least as large as the area of a 2 CSS pixel thick perimeter of the unfocused component or sub-component, and has a contrast ratio of at least 3:1 between the same pixels in the focused and unfocused states.

Exceptions: The focus indicator is determined by the user agent and cannot be adjusted by the author, or The focus indicator and the indicator's background color are not modified by the author. Note 1 What is perceived as the user interface component or sub-component (to determine enclosure or size) depends on its visual presentation . The visual presentation includes the component's visible content , border, and component-specific background. It does not include shadow and glow effects outside the component's content, background, or border. Note 2 Examples of sub-components that may receive a focus indicator are menu items in an opened drop-down menu, or focusable cells in a grid.

Note 3 Contrast calculations can be based on colors defined within the technology (such as HTML, CSS and SVG). Pixels modified by user agent resolution enhancements and anti-aliasing can be ignored. Guideline 2.5 Input Modalities Understanding Input Modalities | How to Meet Input Modalities Make it easier for users to operate functionality through various inputs beyond keyboard. Success Criterion 2.5.1 Pointer Gestures Understanding Pointer Gestures | How to Meet Pointer Gestures (Level A) All functionality that uses multipoint or path-based gestures for operation can be operated with a single pointer without a path-based gesture, unless a multipoint or path-based gesture is essential . Note This requirement applies to web content that interprets pointer actions (i.e.

this does not apply to actions that are required to operate the user agent or assistive technology). Success Criterion 2.5.2 Pointer Cancellation Understanding Pointer Cancellation | How to Meet Pointer Cancellation (Level A) For functionality that can be operated using a single pointer , at least one of the following is true: No Down-Event The down-event of the pointer is not used to execute any part of the function; Abort or Undo Completion of the function is on the up-event , and a mechanism is available to abort the function before completion or to undo the function after completion; Up Reversal The up-event reverses any outcome of the preceding down-event; Essential Completing the function on the down-event is essential . Note 1 Functions that emulate a keyboard or numeric keypad key press are considered essential. Note 2 This requirement applies to web content that interprets pointer actions (i.e. this does not apply to actions that are required to operate the user agent or assistive technology).

Success Criterion 2.5.3 Label in Name Understanding Label in Name | How to Meet Label in Name (Level A) For user interface components with labels that include text or images of text , the name contains the text that is presented visually. Note A best practice is to have the text of the label at the start of the name. Success Criterion 2.5.4 Motion Actuation Understanding Motion Actuation | How to Meet Motion Actuation (Level A) Functionality that can be operated by device motion or user motion can also be operated by user interface components and responding to the motion can be disabled to prevent accidental actuation, except when: Supported Interface The motion is used to operate functionality through an accessibility supported interface; Essential The motion is essential for the function and doing so would invalidate the activity. Success Criterion 2.5.5 Target Size (Enhanced) Understanding Target Size (Enhanced) | How to Meet Target Size (Enhanced) (Level AAA) The size of the target for pointer inputs is at least 44 by 44 CSS pixels except when: Equivalent The target is available through an equivalent link or control on the same page that is at least 44 by 44 CSS pixels; Inline The target is in a sentence or block of text; User Agent Control The size of the target is determined by the user agent and is not modified by the author; Essential A particular presentation of the target is essential to the information being conveyed. Success Criterion 2.5.6 Concurrent Input Mechanisms Understanding Concurrent Input Mechanisms | How to Meet Concurrent Input Mechanisms (Level AAA) Web content does not restrict use of input modalities available on a platform except where the restriction is essential , required to ensure the security of the content, or required to respect user settings.

Success Criterion 2.5.7 Dragging Movements Understanding Dragging Movements | How to Meet Dragging Movements (Level AA) [New] All functionality that uses a dragging movement for operation can be achieved by a single pointer without dragging, unless dragging is essential or the functionality is determined by the user agent and not modified by the author. Note This requirement applies to web content that interprets pointer actions (i.e. this does not apply to actions that are required to operate the user agent or assistive technology). Success Criterion 2.5.8 Target Size (Minimum) Understanding Target Size (Minimum) | How to Meet Target Size (Minimum) (Level AA) [New] The size of the target for pointer inputs is at least 24 by 24 CSS pixels , except where: Spacing: Undersized targets (those less than 24 by 24 CSS pixels) are positioned so that if a 24 CSS pixel diameter circle is centered on the bounding box of each, the circles do not intersect another target or the circle for another undersized target; Equivalent: The function can be achieved through a different control on the same page that meets this criterion; Inline: The target is in a sentence or its size is otherwise constrained by the line-height of non-target text; User agent control: The size of the target is determined by the user agent and is not modified by the author; Essential: A particular presentation of the target is essential or is legally required for the information being conveyed. Note 1 Targets that allow for values to be selected spatially based on position within the target are considered one target for the purpose of the success criterion.

Examples include sliders, color pickers displaying a gradient of colors, or editable areas where you position the cursor. Note 2 For inline targets the line-height should be interpreted as perpendicular to the flow of text. For example, in a language displayed vertically, the line-height would be horizontal. 3. Understandable Information and the operation of the user interface must be understandable.

Guideline 3.1 Readable Understanding Readable | How to Meet Readable Make text content readable and understandable. Success Criterion 3.1.1 Language of Page Understanding Language of Page | How to Meet Language of Page (Level A) The default human language of each Web page can be programmatically determined . Success Criterion 3.1.2 Language of Parts Understanding Language of Parts | How to Meet Language of Parts (Level AA) The human language of each passage or phrase in the content can be programmatically determined except for proper names, technical terms, words of indeterminate language, and words or phrases that have become part of the vernacular of the immediately surrounding text. Success Criterion 3.1.3 Unusual Words Understanding Unusual Words | How to Meet Unusual Words (Level AAA) A mechanism is available for identifying specific definitions of words or phrases used in an unusual or restricted way , including idioms and jargon . Success Criterion 3.1.4 Abbreviations Understanding Abbreviations | How to Meet Abbreviations (Level AAA) A mechanism for identifying the expanded form or meaning of abbreviations is available.

Success Criterion 3.1.5 Reading Level Understanding Reading Level | How to Meet Reading Level (Level AAA) When text requires reading ability more advanced than the lower secondary education level after removal of proper names and titles, supplemental content , or a version that does not require reading ability more advanced than the lower secondary education level, is available. Success Criterion 3.1.6 Pronunciation Understanding Pronunciation | How to Meet Pronunciation (Level AAA) A mechanism is available for identifying specific pronunciation of words where meaning of the words, in context, is ambiguous without knowing the pronunciation. Guideline 3.2 Predictable Understanding Predictable | How to Meet Predictable Make Web pages appear and operate in predictable ways. Success Criterion 3.2.1 On Focus Understanding On Focus | How to Meet On Focus (Level A) When any user interface component receives focus, it does not initiate a change of context . Success Criterion 3.2.2 On Input Understanding On Input | How to Meet On Input (Level A) Changing the setting of any user interface component does not automatically cause a change of context unless the user has been advised of the behavior before using the component.

Success Criterion 3.2.3 Consistent Navigation Understanding Consistent Navigation | How to Meet Consistent Navigation (Level AA) Navigational mechanisms that are repeated on multiple Web pages within a set of Web pages occur in the same relative order each time they are repeated, unless a change is initiated by the user. Success Criterion 3.2.4 Consistent Identification Understanding Consistent Identification | How to Meet Consistent Identification (Level AA) Components that have the same functionality within a set of Web pages are identified consistently. Success Criterion 3.2.5 Change on Request Understanding Change on Request | How to Meet Change on Request (Level AAA) Changes of context are initiated only by user request or a mechanism is available to turn off such changes. Success Criterion 3.2.6 Consistent Help Understanding Consistent Help | How to Meet Consistent Help (Level A) [New] If a Web page contains any of the following help mechanisms , and those mechanisms are repeated on multiple Web pages within a set of Web pages , they occur in the same order relative to other page content, unless a change is initiated by the user: Human contact details; Human contact mechanism; Self-help option; A fully automated contact mechanism. Note 1 Help mechanisms may be provided directly on the page, or may be provided via a direct link to a different page containing the information.

Note 2 For this Success Criterion, "the same order relative to other page content" can be thought of as how the content is ordered when the page is serialized. The visual position of a help mechanism is likely to be consistent across pages for the same page variation (e.g., CSS break-point). The user can initiate a change, such as changing the page's zoom or orientation, which may trigger a different page variation. This criterion is concerned with relative order across pages displayed in the same page variation (e.g., same zoom level and orientation). Guideline 3.3 Input Assistance Understanding Input Assistance | How to Meet Input Assistance Help users avoid and correct mistakes.

Success Criterion 3.3.1 Error Identification Understanding Error Identification | How to Meet Error Identification (Level A) If an input error is automatically detected, the item that is in error is identified and the error is described to the user in text. Success Criterion 3.3.2 Labels or Instructions Understanding Labels or Instructions | How to Meet Labels or Instructions (Level A) Labels or instructions are provided when content requires user input. Success Criterion 3.3.3 Error Suggestion Understanding Error Suggestion | How to Meet Error Suggestion (Level AA) If an input error is automatically detected and suggestions for correction are known, then the suggestions are provided to the user, unless it would jeopardize the security or purpose of the content. Success Criterion 3.3.4 Error Prevention (Legal, Financial, Data) Understanding Error Prevention (Legal, Financial, Data) | How to Meet Error Prevention (Legal, Financial, Data) (Level AA) For Web pages that cause legal commitments or financial transactions for the user to occur, that modify or delete user-controllable data in data storage systems, or that submit user test responses, at least one of the following is true: Reversible Submissions are reversible. Checked Data entered by the user is checked for input errors and the user is provided an opportunity to correct them.

Confirmed A mechanism is available for reviewing, confirming, and correcting information before finalizing the submission. Success Criterion 3.3.5 Help Understanding Help | How to Meet Help (Level AAA) Context-sensitive help is available. Success Criterion 3.3.6 Error Prevention (All) Understanding Error Prevention (All) | How to Meet Error Prevention (All) (Level AAA) For Web pages that require the user to submit information, at least one of the following is true: Reversible Submissions are reversible. Checked Data entered by the user is checked for input errors and the user is provided an opportunity to correct them. Confirmed A mechanism is available for reviewing, confirming, and correcting information before finalizing the submission.

Success Criterion 3.3.7 Redundant Entry Understanding Redundant Entry | How to Meet Redundant Entry (Level A) [New] Information previously entered by or provided to the user that is required to be entered again in the same process is either: auto-populated, or available for the user to select. Except when: re-entering the information is essential , the information is required to ensure the security of the content, or previously entered information is no longer valid. Success Criterion 3.3.8 Accessible Authentication (Minimum) Understanding Accessible Authentication (Minimum) | How to Meet Accessible Authentication (Minimum) (Level AA) [New] A cognitive function test (such as remembering a password or solving a puzzle) is not required for any step in an authentication process unless that step provides at least one of the following: Alternative Another authentication method that does not rely on a cognitive function test. Mechanism A mechanism is available to assist the user in completing the cognitive function test. Object Recognition The cognitive function test is to recognize objects.

Personal Content The cognitive function test is to identify non-text content the user provided to the Web site. Note 1 "Object recognition" and "Personal content" may be represented by images, video, or audio. Note 2 Examples of mechanisms that satisfy this criterion include: support for password entry by password managers to reduce memory need, and copy and paste to reduce the cognitive burden of re-typing. Success Criterion 3.3.9 Accessible Authentication (Enhanced) Understanding Accessible Authentication (Enhanced) | How to Meet Accessible Authentication (Enhanced) (Level AAA) [New] A cognitive function test (such as remembering a password or solving a puzzle) is not required for any step in an authentication process unless that step provides at least one of the following: Alternative Another authentication method that does not rely on a cognitive function test. Mechanism A mechanism is available to assist the user in completing the cognitive function test.

4. Robust Content must be robust enough that it can be interpreted by a wide variety of user agents, including assistive technologies. Guideline 4.1 Compatible Understanding Compatible | How to Meet Compatible Maximize compatibility with current and future user agents, including assistive technologies. Success Criterion 4.1.1 Parsing (Obsolete and removed) Understanding Parsing (Obsolete and removed) | How to Meet Parsing (Obsolete and removed) Note This criterion was originally adopted to address problems that assistive technology had directly parsing HTML. Assistive technology no longer has any need to directly parse HTML.

Consequently, these problems either no longer exist or are addressed by other criteria. This criterion no longer has utility and is removed. Success Criterion 4.1.2 Name, Role, Value Understanding Name, Role, Value | How to Meet Name, Role, Value (Level A) For all user interface components (including but not limited to: form elements, links and components generated by scripts), the name and role can be programmatically determined ; states, properties, and values that can be set by the user can be programmatically set ; and notification of changes to these items is available to user agents , including assistive technologies . Note This success criterion is primarily for Web authors who develop or script their own user interface components. For example, standard HTML controls already meet this success criterion when used according to specification.

Success Criterion 4.1.3 Status Messages Understanding Status Messages | How to Meet Status Messages (Level AA) In content implemented using markup languages, status messages can be programmatically determined through role or properties such that they can be presented to the user by assistive technologies without receiving focus. 5. Conformance This section lists requirements for conformance to WCAG 2.2. It also gives information about how to make conformance claims, which are optional. Finally, it describes what it means to be accessibility supported , since only accessibility-supported ways of using technologies can be relied upon for conformance.

Understanding Conformance includes further explanation of the accessibility-supported concept. 5.1 Interpreting Normative Requirements The main content of WCAG 2.2 is normative and defines requirements that impact conformance claims. Introductory material, appendices, sections marked as "non-normative", diagrams, examples, and notes are informative (non-normative). Non-normative material provides advisory information to help interpret the guidelines but does not create requirements that impact a conformance claim. The key words MAY , MUST , MUST NOT , NOT RECOMMENDED , RECOMMENDED , SHOULD , and SHOULD NOT are to be interpreted as described in [ RFC2119 ].

5.2 Conformance Requirements In order for a Web page to conform to WCAG 2.2, all of the following conformance requirements must be satisfied: 5.2.1 Conformance Level One of the following levels of conformance is met in full. For Level A conformance (the minimum level of conformance), the Web page satisfies all the Level A Success Criteria, or a conforming alternate version is provided. For Level AA conformance, the Web page satisfies all the Level A and Level AA Success Criteria, or a Level AA conforming alternate version is provided. For Level AAA conformance, the Web page satisfies all the Level A, Level AA and Level AAA Success Criteria, or a Level AAA conforming alternate version is provided. Note 1 Although conformance can only be achieved at the stated levels, authors are encouraged to report (in their claim) any progress toward meeting success criteria from all levels beyond the achieved level of conformance.

Note 2 It is not recommended that Level AAA conformance be required as a general policy for entire sites because it is not possible to satisfy all Level AAA Success Criteria for some content. 5.2.2 Full pages Conformance (and conformance level) is for full Web page(s) only, and cannot be achieved if part of a Web page is excluded. Note 1 For the purpose of determining conformance, alternatives to part of a page's content are considered part of the page when the alternatives can be obtained directly from the page, e.g., a long description or an alternative presentation of a video. Note 2 Authors of Web pages that cannot conform due to content outside of the author's control may consider a Statement of Partial Conformance . Note 3 A full page includes each variation of the page that is automatically presented by the page for various screen sizes (e.g.

variations in a responsive Web page). Each of these variations needs to conform (or needs to have a conforming alternate version) in order for the entire page to conform. 5.2.3 Complete processes When a Web page is one of a series of Web pages presenting a process (i.e., a sequence of steps that need to be completed in order to accomplish an activity), all Web pages in the process conform at the specified level or better. (Conformance is not possible at a particular level if any page in the process does not conform at that level or better.) Example An online store has a series of pages that are used to select and purchase products. All pages in the series from start to finish (checkout) conform in order for any page that is part of the process to conform. 5.2.4 Only Accessibility-Supported Ways of Using Technologies Only accessibility-supported ways of using technologies are relied upon to satisfy the success criteria.

Any information or functionality that is provided in a way that is not accessibility supported is also available in a way that is accessibility supported. (See Understanding accessibility support .) 5.2.5 Non-Interference If technologies are used in a way that is not accessibility supported , or if they are used in a non-conforming way, then they do not block the ability of users to access the rest of the page. In addition, the Web page as a whole continues to meet the conformance requirements under each of the following conditions: when any technology that is not relied upon is turned on in a user agent, when any technology that is not relied upon is turned off in a user agent, and when any technology that is not relied upon is not supported by a user agent In addition, the following success criteria apply to all content on the page, including content that is not otherwise relied upon to meet conformance, because failure to meet them could interfere with any use of the page: 1.4.2 - Audio Control , 2.1.2 - No Keyboard Trap , 2.3.1 - Three Flashes or Below Threshold , and 2.2.2 - Pause, Stop, Hide . Note If a page cannot conform (for example, a conformance test page or an example page), it cannot be included in the scope of conformance or in a conformance claim. For more information, including examples, see Understanding Conformance Requirements .

5.3 Conformance Claims (Optional) Conformance is defined only for Web pages . However, a conformance claim may be made to cover one page, a series of pages, or multiple related Web pages. 5.3.1 Required Components of a Conformance Claim Conformance claims are not required . Authors can conform to WCAG 2.2 without making a claim. However, if a conformance claim is made, then the conformance claim must include the following information: Date of the claim Guidelines title, version and URI "Web Content Accessibility Guidelines 2.2 at https://www.w3.org/TR/WCAG22/ " Conformance level satisfied: (Level A, AA or AAA) A concise description of the Web pages , such as a list of URIs for which the claim is made, including whether subdomains are included in the claim.

Note 1 The Web pages may be described by list or by an expression that describes all of the URIs included in the claim. Note 2 Web-based products that do not have a URI prior to installation on the customer's Web site may have a statement that the product would conform when installed. A list of the Web content technologies relied upon . Note 3 If a conformance logo is used, it would constitute a claim and must be accompanied by the required components of a conformance claim listed above. 5.3.2 Optional Components of a Conformance Claim In addition to the required components of a conformance claim above, consider providing additional information to assist users.

Recommended additional information includes: A list of success criteria beyond the level of conformance claimed that have been met. This information should be provided in a form that users can use, preferably machine-readable metadata. A list of the specific technologies that are " used but not relied upon ." A list of user agents, including assistive technologies that were used to test the content. A list of specific accessibility characteristics of the content, provided in machine-readable metadata. Information about any additional steps taken that go beyond the success criteria to enhance accessibility.

A machine-readable metadata version of the list of specific technologies that are relied upon . A machine-readable metadata version of the conformance claim. Note 1 Refer to Understanding Conformance Claims for more information and example conformance claims. Note 2 Refer to Understanding Metadata for more information about the use of metadata in conformance claims. 5.4 Statement of Partial Conformance - Third Party Content Web pages that will later have additional content added can use a 'statement of partial conformance'.

For example, an email program, a blog, an article that allows users to add comments, or applications supporting user-contributed content. Another example would be a page, such as a portal or news site, composed of content aggregated from multiple contributors, or sites that automatically insert content from other sources over time, such as when advertisements are inserted dynamically. In these cases, it is not possible to know at the time of original posting what the uncontrolled content of the pages will be. It is important to note that the uncontrolled content can affect the accessibility of the controlled content as well. Two options are available: A determination of conformance can be made based on best knowledge.

If a page of this type is monitored and repaired (non-conforming content is removed or brought into conformance) within two business days, then a determination or claim of conformance can be made since, except for errors in externally contributed content which are corrected or removed when encountered, the page conforms. No conformance claim can be made if it is not possible to monitor or correct non-conforming content; OR A "statement of partial conformance" may be made that the page does not conform, but could conform if certain parts were removed. The form of that statement would be, "This page does not conform, but would conform to WCAG 2.2 at level X if the following parts from uncontrolled sources were removed." In addition, the following would also be true of uncontrolled content that is described in the statement of partial conformance: It is not content that is under the author's control. It is described in a way that users can identify (e.g., they cannot be described as "all parts that we do not control" unless they are clearly marked as such.) 5.5 Statement of Partial Conformance - Language A "statement of partial conformance due to language" may be made when the page does not conform, but would conform if accessibility support existed for (all of) the language(s) used on the page. The form of that statement would be, "This page does not conform, but would conform to WCAG 2.2 at level X if accessibility support existed for the following language(s):" 5.6 Privacy Considerations This section is non-normative.

Success Criteria within this specification which the Working Group has identified possible implications for privacy, either by providing protections for end users or which are important for web site providers to take in to consideration when implementing features designed to protect user privacy, are listed below. This list reflects the current understanding of the Working Group but other Success Criteria may have privacy implications that the Working Group is not aware of at the time of publishing. Success Criteria within this specification that may relate to privacy are: 2.2.6 Timeouts (AAA) 3.3.7 Redundant Entry (A) 5.7 Security Considerations This section is non-normative. Success Criteria within this specification which the Working Group has identified possible implications for security, either by providing protections for end users or which are important for web site providers to take in to consideration when implementing features designed to protect user security, are listed below. This list reflects the current understanding of the Working Group but other Success Criteria may have security implications that the Working Group is not aware of at the time of publishing.

Success Criteria within this specification that may relate to security are: 1.1.1 Non-text Content (A) 1.3.5 Identify Input Purpose (AA) 1.4.7 Low or No Background Audio (AAA) 2.2.1 Timing Adjustable (A) 2.2.5 Re-authenticating (AAA) 2.2.6 Timeouts (AAA) 2.5.6 Concurrent Input Mechanisms (AAA) 3.3.3 Error Suggestion (AA) 3.3.7 Redundant Entry (A) 3.3.8 Accessible Authentication (Minimum) (AA) 3.3.9 Accessible Authentication (Enhanced) (AAA) 6. Glossary abbreviation shortened form of a word, phrase, or name where the abbreviation has not become part of the language Note 1 This includes initialisms and acronyms where: initialisms are shortened forms of a name or phrase made from the initial letters of words or syllables contained in that name or phrase Note 2 Not defined in all languages. Example 1 SNCF is a French initialism that contains the initial letters of the Société Nationale des Chemins de Fer , the French national railroad. Example 2 ESP is an initialism for extrasensory perception. acronyms are abbreviated forms made from the initial letters or parts of other words (in a name or phrase) which may be pronounced as a word Example 3 NOAA is an acronym made from the initial letters of the National Oceanic and Atmospheric Administration in the United States.

Note 3 Some companies have adopted what used to be an initialism as their company name. In these cases, the new name of the company is the letters (for example, Ecma) and the word is no longer considered an abbreviation. accessibility supported supported by users' assistive technologies as well as the accessibility features in browsers and other user agents To qualify as an accessibility-supported use of a Web content technology (or feature of a technology), both 1 and 2 must be satisfied for a Web content technology (or feature): The way that the Web content technology is used must be supported by users' assistive technology (AT). This means that the way that the technology is used has been tested for interoperability with users' assistive technology in the human language(s) of the content, AND The Web content technology must have accessibility-supported user agents that are available to users. This means that at least one of the following four statements is true: The technology is supported natively in widely-distributed user agents that are also accessibility supported (such as HTML and CSS); OR The technology is supported in a widely-distributed plug-in that is also accessibility supported; OR The content is available in a closed environment, such as a university or corporate network, where the user agent required by the technology and used by the organization is also accessibility supported; OR The user agent(s) that support the technology are accessibility supported and are available for download or purchase in a way that: does not cost a person with a disability any more than a person without a disability and is as easy to find and obtain for a person with a disability as it is for a person without disabilities.

Note 1 The Accessibility Guidelines Working Group and the W3C do not specify which or how much support by assistive technologies there must be for a particular use of a Web technology in order for it to be classified as accessibility supported. (See Level of Assistive Technology Support Needed for "Accessibility Support" .) Note 2 Web technologies can be used in ways that are not accessibility supported as long as they are not relied upon and the page as a whole meets the conformance requirements, including Conformance Requirement 4 and Conformance Requirement 5 . Note 3 When a Web Technology is used in a way that is "accessibility supported," it does not imply that the entire technology or all uses of the technology are supported. Most technologies, including HTML, lack support for at least one feature or use. Pages conform to WCAG only if the uses of the technology that are accessibility supported can be relied upon to meet WCAG requirements.

Note 4 When citing Web content technologies that have multiple versions, the version(s) supported should be specified. Note 5 One way for authors to locate uses of a technology that are accessibility supported would be to consult compilations of uses that are documented to be accessibility supported. (See Understanding Accessibility-Supported Web Technology Uses .) Authors, companies, technology vendors, or others may document accessibility-supported ways of using Web content technologies. However, all ways of using technologies in the documentation would need to meet the definition of accessibility-supported Web content technologies above. alternative for time-based media document including correctly sequenced text descriptions of time-based visual and auditory information and providing a means for achieving the outcomes of any time-based interaction Note A screenplay used to create the synchronized media content would meet this definition only if it was corrected to accurately represent the final synchronized media after editing. ambiguous to users in general the purpose cannot be determined from the link and all information of the Web page presented to the user simultaneously with the link (i.e., readers without disabilities would not know what a link would do until they activated it) Example The word guava in the following sentence "One of the notable exports is guava" is a link.

The link could lead to a definition of guava, a chart listing the quantity of guava exported or a photograph of people harvesting guava. Until the link is activated, all readers are unsure and the person with a disability is not at any disadvantage. ASCII art picture created by a spatial arrangement of characters or glyphs (typically from the 95 printable characters defined by ASCII) assistive technology (as used in this document) hardware and/or software that acts as a user agent , or along with a mainstream user agent, to provide functionality to meet the requirements of users with disabilities that go beyond those offered by mainstream user agents Note 1 Functionality provided by assistive technology includes alternative presentations (e.g., as synthesized speech or magnified content), alternative input methods (e.g., voice), additional navigation or orientation mechanisms, and content transformations (e.g., to make tables more accessible). Note 2 Assistive technologies often communicate data and messages with mainstream user agents by using and monitoring APIs. Note 3 The distinction between mainstream user agents and assistive technologies is not absolute. Many mainstream user agents provide some features to assist individuals with disabilities. The basic difference is that mainstream user agents target broad and diverse audiences that usually include people with and without disabilities.

Assistive technologies target narrowly defined populations of users with specific disabilities. The assistance provided by an assistive technology is more specific and appropriate to the needs of its target users. The mainstream user agent may provide important functionality to assistive technologies like retrieving Web content from program objects or parsing markup into identifiable bundles. Example Assistive technologies that are important in the context of this document include the following: screen magnifiers, and other visual reading assistants, which are used by people with visual, perceptual and physical print disabilities to change text font, size, spacing, color, synchronization with speech, etc. in order to improve the visual readability of rendered text and images; screen readers, which are used by people who are blind to read textual information through synthesized speech or braille; text-to-speech software, which is used by some people with cognitive, language, and learning disabilities to convert text into synthetic speech; speech recognition software, which may be used by people who have some physical disabilities; alternative keyboards, which are used by people with certain physical disabilities to simulate the keyboard (including alternate keyboards that use head pointers, single switches, sip/puff and other special input devices.); alternative pointing devices, which are used by people with certain physical disabilities to simulate mouse pointing and button activations.

audio the technology of sound reproduction Note Audio can be created synthetically (including speech synthesis), recorded from real world sounds, or both. audio description narration added to the soundtrack to describe important visual details that cannot be understood from the main soundtrack alone Note 1 Audio description of video provides information about actions, characters, scene changes, on-screen text, and other visual content. Note 2 In standard audio description, narration is added during existing pauses in dialogue. (See also extended audio description .) Note 3 Where all of the video information is already provided in existing audio , no additional audio description is necessary. Note 4 Also called "video description" and "descriptive narration." audio-only a time-based presentation that contains only audio (no video and no interaction) blinking switch back and forth between two visual states in a way that is meant to draw attention Note See also flash . It is possible for something to be large enough and blink brightly enough at the right frequency to be also classified as a flash.

blocks of text more than one sentence of text CAPTCHA initialism for "Completely Automated Public Turing test to tell Computers and Humans Apart" Note 1 CAPTCHA tests often involve asking the user to type in text that is displayed in an obscured image or audio file. Note 2 A Turing test is any system of tests designed to differentiate a human from a computer. It is named after famed computer scientist Alan Turing. The term was coined by researchers at Carnegie Mellon University. captions synchronized visual and/or text alternative for both speech and non-speech audio information needed to understand the media content Note 1 Captions are similar to dialogue-only subtitles except captions convey not only the content of spoken dialogue, but also equivalents for non-dialogue audio information needed to understand the program content, including sound effects, music, laughter, speaker identification and location. Note 2 Closed Captions are equivalents that can be turned on and off with some players.

Note 3 Open Captions are any captions that cannot be turned off. For example, if the captions are visual equivalent images of text embedded in video . Note 4 Captions should not obscure or obstruct relevant information in the video. Note 5 In some countries, captions are called subtitles. Note 6 Audio descriptions can be, but do not need to be, captioned since they are descriptions of information that is already presented visually.

changes of context major changes that, if made without user awareness, can disorient users who are not able to view the entire page simultaneously Changes in context include changes of: user agent ; viewport ; focus; content that changes the meaning of the Web page Note A change of content is not always a change of context. Changes in content, such as an expanding outline, dynamic menu, or a tab control do not necessarily change the context, unless they also change one of the above (e.g., focus). Example Opening a new window, moving focus to a different component, going to a new page (including anything that would look to a user as if they had moved to a new page) or significantly re-arranging the content of a page are examples of changes of context. Cognitive function test [New] A task that requires the user to remember, manipulate, or transcribe information. Examples include, but are not limited to: memorization, such as remembering a username, password, set of characters, images, or patterns.

The common identifiers name, e-mail, and phone number are not considered cognitive function tests as they are personal to the user and consistent across Web sites; transcription, such as typing in characters; use of correct spelling; performance of calculations; solving of puzzles. conformance satisfying all the requirements of a given standard, guideline or specification conforming alternate version version that conforms at the designated level, and provides all of the same information and functionality in the same human language , and is as up to date as the non-conforming content, and for which at least one of the following is true: the conforming version can be reached from the non-conforming page via an accessibility-supported mechanism , or the non-conforming version can only be reached from the conforming version, or the non-conforming version can only be reached from a conforming page that also provides a mechanism to reach the conforming version Note 1 In this definition, "can only be reached" means that there is some mechanism, such as a conditional redirect, that prevents a user from "reaching" (loading) the non-conforming page unless the user had just come from the conforming version. Note 2 The alternate version does not need to be matched page for page with the original (e.g., the conforming alternate version may consist of multiple pages). Note 3 If multiple language versions are available, then conforming alternate versions are required for each language offered. Note 4 Alternate versions may be provided to accommodate different technology environments or user groups.

Each version should be as conformant as possible. One version would need to be fully conformant in order to meet conformance requirement 1 . Note 5 The conforming alternative version does not need to reside within the scope of conformance, or even on the same Web site, as long as it is as freely available as the non-conforming version. Note 6 Alternate versions should not be confused with supplementary content , which support the original page and enhance comprehension. Note 7 Setting user preferences within the content to produce a conforming version is an acceptable mechanism for reaching another version as long as the method used to set the preferences is accessibility supported.

See Understanding Conforming Alternate Versions content (Web content) information and sensory experience to be communicated to the user by means of a user agent , including code or markup that defines the content's structure , presentation , and interactions context-sensitive help help text that provides information related to the function currently being performed Note Clear labels can act as context-sensitive help. contrast ratio (L1 + 0.05) / (L2 + 0.05), where L1 is the relative luminance of the lighter of the colors, and L2 is the relative luminance of the darker of the colors. Note 1 Contrast ratios can range from 1 to 21 (commonly written 1:1 to 21:1). Note 2 Because authors do not have control over user settings as to how text is rendered (for example font smoothing or anti-aliasing), the contrast ratio for text can be evaluated with anti-aliasing turned off. Note 3 For the purpose of Success Criteria 1.4.3 and 1.4.6, contrast is measured with respect to the specified background over which the text is rendered in normal usage.

If no background color is specified, then white is assumed. Note 4 Background color is the specified color of content over which the text is to be rendered in normal usage. It is a failure if no background color is specified when the text color is specified, because the user's default background color is unknown and cannot be evaluated for sufficient contrast. For the same reason, it is a failure if no text color is specified when a background color is specified. Note 5 When there is a border around the letter, the border can add contrast and would be used in calculating the contrast between the letter and its background.

A narrow border around the letter would be used as the letter. A wide border around the letter that fills in the inner details of the letters acts as a halo and would be considered background. Note 6 WCAG conformance should be evaluated for color pairs specified in the content that an author would expect to appear adjacent in typical presentation. Authors need not consider unusual presentations, such as color changes made by the user agent, except where caused by authors' code. correct reading sequence any sequence where words and paragraphs are presented in an order that does not change the meaning of the content CSS pixel visual angle of about 0.0213 degrees A CSS pixel is the canonical unit of measure for all lengths and measurements in CSS. This unit is density-independent, and distinct from actual hardware pixels present in a display.

User agents and operating systems should ensure that a CSS pixel is set as closely as possible to the CSS Values and Units Module Level 3 reference pixel [ css3-values ], which takes into account the physical dimensions of the display and the assumed viewing distance (factors that cannot be determined by content authors). down-event platform event that occurs when the trigger stimulus of a pointer is depressed The down-event may have different names on different platforms, such as "touchstart" or "mousedown". dragging movement [New] an operation where the pointer engages with an element on the down-event and the element (or a representation of its position) follows the pointer until an up-event Note Examples of draggable elements include list items, text elements, and images. emergency a sudden, unexpected situation or occurrence that requires immediate action to preserve health, safety, or property encloses [New] solidly bounds or surrounds essential if removed, would fundamentally change the information or functionality of the content, and information and functionality cannot be achieved in another way that would conform extended audio description audio description that is added to an audiovisual presentation by pausing the video so that there is time to add additional description Note This technique is only used when the sense of the video would be lost without the additional audio description and the pauses between dialogue/narration are too short. flash a pair of opposing changes in relative luminance that can cause seizures in some people if it is large enough and in the right frequency range Note 1 See general flash and red flash thresholds for information about types of flash that are not allowed.

Note 2 See also blinking . focus indicator [New] pixels that are changed to visually indicate when a user interface component is in a focused state functionality processes and outcomes achievable through user action general flash and red flash thresholds a flash or rapidly changing image sequence is below the threshold (i.e., content passes ) if any of the following are true: there are no more than three general flashes and / or no more than three red flashes within any one-second period; or the combined area of flashes occurring concurrently occupies no more than a total of .006 steradians within any 10 degree visual field on the screen (25% of any 10 degree visual field on the screen) at typical viewing distance where: A general flash is defined as a pair of opposing changes in relative luminance of 10% or more of the maximum relative luminance (1.0) where the relative luminance of the darker image is below 0.80; and where "a pair of opposing changes" is an increase followed by a decrease, or a decrease followed by an increase, and A red flash is defined as any pair of opposing transitions involving a saturated red Exception: Flashing that is a fine, balanced, pattern such as white noise or an alternating checkerboard pattern with "squares" smaller than 0.1 degree (of visual field at typical viewing distance) on a side does not violate the thresholds. Note 1 For general software or Web content, using a 341 x 256 pixel rectangle anywhere on the displayed screen area when the content is viewed at 1024 x 768 pixels will provide a good estimate of a 10 degree visual field for standard screen sizes and viewing distances (e.g., 15-17 inch screen at 22-26 inches). This resolution of 75 - 85 ppi is known to be lower, and thus more conservative than the nominal CSS pixel resolution of 96 ppi in CSS specifications. Higher resolutions displays showing the same rendering of the content yield smaller and safer images so it is lower resolutions that are used to define the thresholds.

Note 2 A transition is the change in relative luminance (or relative luminance/color for red flashing) between adjacent peaks and valleys in a plot of relative luminance (or relative luminance/color for red flashing) measurement against time. A flash consists of two opposing transitions. Note 3 The new working definition in the field for "pair of opposing transitions involving a saturated red" (from WCAG 2.2) is a pair of opposing transitions where, one transition is either to or from a state with a value R/(R + G + B) that is greater than or equal to 0.8, and the difference between states is more than 0.2 (unitless) in the CIE 1976 UCS chromaticity diagram. [ ISO_9241-391 ] Note 4 Tools are available that will carry out analysis from video screen capture. However, no tool is necessary to evaluate for this condition if flashing is less than or equal to 3 flashes in any one second.

Content automatically passes (see #1 and #2 above). human language language that is spoken, written or signed (through visual or tactile means) to communicate with humans Note See also sign language . idiom phrase whose meaning cannot be deduced from the meaning of the individual words and the specific words cannot be changed without losing the meaning Note Idioms cannot be translated directly, word for word, without losing their (cultural or language-dependent) meaning. Example 1 In English, "spilling the beans" means "revealing a secret." However, "knocking over the beans" or "spilling the vegetables" does not mean the same thing. Example 2 In Japanese, the phrase " さじを投げる " literally translates into "he throws a spoon," but it means that there is nothing he can do and finally he gives up.

Example 3 In Dutch, " Hij ging met de kippen op stok " literally translates into "He went to roost with the chickens," but it means that he went to bed early. image of text text that has been rendered in a non-text form (e.g., an image) in order to achieve a particular visual effect Note This does not include text that is part of a picture that contains significant other visual content. Example A person's name on a nametag in a photograph. informative for information purposes and not required for conformance Note Content required for conformance is referred to as " normative ." input error information provided by the user that is not accepted Note This includes: Information that is required by the Web page but omitted by the user Information that is provided by the user but that falls outside the required data format or values jargon words used in a particular way by people in a particular field Example The word StickyKeys is jargon from the field of assistive technology/accessibility. keyboard interface interface used by software to obtain keystroke input Note 1 A keyboard interface allows users to provide keystroke input to programs even if the native technology does not contain a keyboard.

Example A touchscreen PDA has a keyboard interface built into its operating system as well as a connector for external keyboards. Applications on the PDA can use the interface to obtain keyboard input either from an external keyboard or from other applications that provide simulated keyboard output, such as handwriting interpreters or speech-to-text applications with "keyboard emulation" functionality. Note 2 Operation of the application (or parts of the application) through a keyboard-operated mouse emulator, such as MouseKeys, does not qualify as operation through a keyboard interface because operation of the program is through its pointing device interface, not through its keyboard interface. keyboard shortcut alternative means of triggering an action by the pressing of one or more keys label text or other component with a text alternative that is presented to a user to identify a component within Web content Note 1 A label is presented to all users whereas the name may be hidden and only exposed by assistive technology. In many (but not all) cases the name and the label are the same.

Note 2 The term label is not limited to the label element in HTML. large scale (text) with at least 18 point or 14 point bold or font size that would yield equivalent size for Chinese, Japanese and Korean (CJK) fonts Note 1 Fonts with extraordinarily thin strokes or unusual features and characteristics that reduce the familiarity of their letter forms are harder to read, especially at lower contrast levels. Note 2 Font size is the size when the content is delivered. It does not include resizing that may be done by a user. Note 3 The actual size of the character that a user sees is dependent both on the author-defined size and the user's display or user agent settings.