YSlow 2.1.0 is now available (courtesy of Marcel Duran). There are major bug fixes in this release, as well as making YSlow compatible with Firefox 4.
YSlow is a Firefox add-on integrated with the Firebug web development tool. It analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages.
Summary of bugs fixed
- Compatible with latest Firefox 3.6., as well as Firefox 4 Beta.
- Compatible with Firebug 1.6 beta
- Updated JSLint version (2010-09-16)
- Improved error message display (removed pop-up, using console instead for error message)
- Fixed some infinite loops issues for redirects and some autorun weird behavior.
- Added new rule for detecting empty src or href (<img src='' >, <link href=>, and <script src=>) as suggested in Nicholas Zakas' NCZOnline.
- Added logic to not consider deferred scripts on head as offenders — previous version of YSlow complains when scripts tags are inserted dynamically into the HEAD tag. Such scripts do not block page rendering and are downloaded in parallel with other resources.
- Fixed inconsistency in displaying Expires date inside YSlow report Summary View column
- Fixed issue running JSLint from a page loaded from a previous