Firefox Beta
Release Notes

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 Beta

April 27, 2016

Version 47.0beta, first offered to Beta channel users on April 27, 2016


  • Support for Google’s Widevine CDM on Windows and Mac OS X so streaming services like Amazon Video can switch from Silverlight to encrypted HTML5 video.

  • Enable VP9 video codec for users with fast machines

  • Embedded YouTube videos now play with HTML5 video if Flash is not installed.

  • Allow no-cache on back/forward navigations for https resources

  • Embedded YouTube videos now play with HTML5 video if Flash is not installed



  • Developer Information
  • See Firefox run! Review Firefox performance data in about:performance.

  • Smart multi-line input in the Web Console

  • Custom user agents supported in Responsive Design Mode

  • Simulate Push messages in the Service Workers developer tool

  • View, start,and debug registered Service Workers in the Service Workers developer tool

  • 'Start' button for service workers in about:debugging to start registered Service Workers

  • Tilt is available as extension on AMO

  • Added support for ChaCha20/Poly1305 cipher suites

  • Changes that can affect add-on compatibility

Web Platform

  • WebCrypto: RSA-PSS signature support

  • WebCrypto: PBKDF2 supports SHA-2 hash algorithms

  • cuechange events are now available on TextTrack objects

All Firefox Beta downloads