Firefox Release

August 11, 2015

Version 40.0, first offered to Release channel users on August 11, 2015

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


  • Support for Windows 10

  • Added protection against unwanted software downloads

  • User can receive suggested tiles in the new tab page based on categories Firefox matches to browsing history (en-US only).

  • Hello allows adding a link to conversations to provide context on what the conversation will be about

  • New style for add-on manager based on the in-content preferences style

  • Improved scrolling, graphics, and video playback performance with off main thread compositing (GNU/Linux only)

  • Graphic blocklist mechanism improved: Firefox version ranges can be specified, limiting the number of devices blocked


  • Kannada text does not display properly in built-in pdf viewer

  • Various security fixes



Web Platform


  • If Firefox is restarted from an add-on install notification, on-going private browsing downloads might be canceled without warning (1185294)

  • Starting in offline mode does not work (1179779)

All Firefox downloads