See what’s new in Firefox!

Release Notes tell you what’s new in Firefox. As always, we welcome your feedback. You can also file a bug in Bugzilla or see the system requirements of this release.

21.0

Firefox for Android Release

May 14, 2013

Version 21.0, first offered to Release channel users on May 14, 2013

New

Fixed

Changed

  • Ability to restore removed thumbnails on New tab Page

  • Add-ons History API removals in Places

  • XBL Scopes Enabled (bugs 834697)

  • CSS -moz-user-select:none selection changed to improve compatibility with -webkit-user-select:none (bug 816298)

  • Removed E4X support from Spidermonkey

  • Graphics related performance improvements (bug 809821)

Developer

  • Implemented Remote Profiling

  • Integrated, Add-on SDK loader and API libraries into Firefox

Developer Information

Web Platform

  • Browsing and Download history clearing needs unification to avoid confusion on clearing download history

  • Some function keys may not work when pressed

unresolved

  • If you try to start Firefox using a locked profile, it will crash (see 573369)