---
title: YSlow
type: service

links:
  -
    text: YSlow
    type: official
    url: http://yslow.org/
  -
    text: the YSlow ruleset matrix
    type: more-info
    url: http://yslow.org/ruleset-matrix/
---

YSlow is another first step for auditing, identifying major bottlenecks in a site's performance. Install the browser extension (or use the API via Grunt) and YSlow gives an overall grade of A-F performance, with itemized issues explaining the problems and possible solutions. One interesting difference between <abbr title="PageSpeed Insights">PSI</abbr> and YSlow is that it has a published matrix explaining how the grade is determined.
