List of Google Easter eggs

The technology company Google has added Easter eggs and April Fools' Day jokes and hoaxes into many of its products and services, such as Google Search, YouTube, and Android since at least 2000.
Easter eggs are hidden features or messages, inside jokes, and cultural references inserted into media. They are often well hidden, so that users find it gratifying when they discover them, helping form bonds between their creators and finders. Google's employees are encouraged to use 20% of their time for projects of personal interest, and Easter eggs are sometimes created during this. Google avoids adding Easter eggs to popular search pages, as they do not want to negatively impact usability.
Search engine.
As Google searches are case insensitive, search terms are listed in lower case except where case sensitivity is explicitly referenced.
A Google web search for:
Did you mean.
A Google web search for:
Knowledge Graph.
A Google web search for:
Friends characters
For the 25th anniversary of the TV series "Friends", Google embedded Easter eggs for , , , , and in their respective Knowledge Graphs.
Embedded tools.
A Google web search for:
Google birthday surprise spinner.
Searching for "" will result in a wheel that spins to one of a selection of playable Google Doodles, tools (see above) and games. Whichever is randomly selected may be opened, or the wheel may be spun again. It was added in celebration of Google's 19th birthday.
Calculator.
In late 2011 Google added a graphical calculator to search results, using natural language processing to determine that search results might be mathematical in nature. Woven into this feature are several, not entirely academic, results which might be considered Easter eggs.
A Google web search for:
The result of multiple Easter eggs may be calculated; for example: "" will return "43".
Ahead of Pi Day 2021, Google added an easter egg game to the calculator tool which tested players' knowledge and memory of Pi.
Google homepage.
Google languages.
Google offers interfaces for several different fictional languages. Users can set any of these languages (except pig Latin) as their search settings' preferred language.
YouTube.
YouTube search.
A YouTube search for: