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.

40.0

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!

New

  • 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

Fixed

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

  • Various security fixes

Changed

Developer

Developer Information

HTML5

unresolved

  • 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)