Firefox Release

September 20, 2016

Version 49.0, first offered to Release channel users on September 20, 2016

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


  • Updated Firefox Login Manager to allow HTTPS pages to use saved HTTP logins. It’s one more way Firefox is supporting Let’s Encrypt and helping users transition to a more secure web.

  • Added features to Reader Mode that make it easier on the eyes and the ears

    • Controls that allow users to adjust the width and line spacing of
    • Narrate, which reads the content of a page out loud
  • Improved video performance for users on systems that support SSSE3 without hardware acceleration

  • Added context menu controls to HTML5 audio and video that let users loops files or play files at 1.25x speed

  • Enhancements for Mac users

    • Improved performance on OS X systems without hardware acceleration
    • Improved appearance of anti-aliased OS X fonts
  • Improvements in about:memory reports for tracking font memory usage

  • Improve performance on Windows systems without hardware acceleration

  • Support of Widevine CDM through the EME API under GNU/Linux


  • Fixed an issue that prevented users from updating Firefox for Mac unless they originally installed Firefox. Now, those users as well as any user with administrative credentials can update Firefox.

  • Various security fixes


  • Ended Firefox for Mac support for OS X 10.6, 10.7, and 10.8.

  • Ended Firefox for Windows support for SSE processors

  • Removed Firefox Hello

  • Re-enabled the default for Graphite2 font shaping

  • UPDATE: 2016-10-17. Asynchronous rendering of the Flash plugins is now enabled by default. This should improve performance and reduce crashes for sites that use the Flash plugin.

  • UPDATE: 2016-10-17. Default preference layers.allow-d3d9-fallback set to false, to fix graphics glitches for some users.

  • Default search engine changed to Yahoo for Chinese (Traditional) locale.

  • Block some nonessential Flash plugin content



All Firefox downloads