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.


Firefox Release

December 1, 2014

Version 34.0.5, first offered to Release channel users on December 1, 2014

We'd also like to extend a special thank you to all of the new Mozillians who contributed to this release of Firefox!


  • Default search engine changed to Yahoo! for North America

  • Default search engine changed to Yandex for Belarusian, Kazakh, and Russian locales

  • Improved search bar (en-US only)

  • Firefox Hello real-time communication client

  • Easily switch themes/personas directly in the Customizing mode

  • Wikipedia search now uses HTTPS for secure searching (en-US only)

  • Recover from a locked Firefox process in the "Firefox is already running" dialog on Windows


  • CSS transitions start correctly when started at the same time as changes to display, position, overflow, and similar properties

  • Various security fixes

  • Fullscreen video on Mac disables display sleep, and dimming, during playback

  • Various Yosemite visual fixes (see bug 1040250)


  • Firefox signed by Apple OS X version 2 signature

  • Proprietary window.crypto properties/functions re-enabled (to be removed in Firefox 35)

  • Disabled SSLv3


  • Improved User Interface of the Profiler

  • Highlight all nodes that match a given selector in the Style Editor and the Inspector's Rules panel

  • console.table function added to web console

  • WebIDE: Create, edit, and test a new Web application from your browser

Developer Information


  • WebCrypto: ECDH support

  • for workers implemented

  • matches() DOM API implemented (formerly mozMatchesSelector())

  • WebCrypto: Import/export of JWK-formatted keys

  • WebCrypto: wrapKey and unwrapKey implemented

  • WebCrypto: RSA-OAEP, PBKDF2 and AES-KW support

  • CSS3 Font variants and features control (e.g. kerning) implemented

  • JavaScript Template Strings Implemented

  • ECMAScript 6 WeakSet Implemented