YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages. YSlow is a Firefox add-on integrated with the Firebug web development tool. YSlow grades web page based on one of three predefined ruleset or a user-defined ruleset. It offers suggestions for improving the page’s performance, summarizes the page’s components, displays statistics about the page, and provides tools for performance analysis, including Smush.it™ and JSLint.
YSlow is licensed under the Mozilla Public License (MPL) version 1.1, with portions licensed by third parties under other license terms. To review the terms before installing, see http://developer.yahoo.com/yslow/faq.html#faq_license.
YSlow uses Yahoo!’s Smush.it service, which is subject to Smush.it Terms of Use: http://info.yahoo.com/legal/us/yahoo/smush_it/smush_it-4378.html
