Firefox Beta Notes

Version 40.0beta, first offered to Beta channel users on July 3, 2015

Check out "What’s New" and "Known Issues" for this version of Firefox below. As always, you’re encouraged to tell us what you think, or file a bug in Bugzilla. If interested, please see the complete list of changes in this release.

What’s New

  • New

    Support for Windows 10

  • New

    Download protection from potentially unwanted software

  • New

    Suggested Tiles show sites that may be of interest, based on categories from your recent browsing history

  • New

    Add URLs to a Hello conversation for additional context

  • New

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

  • New

    Smoother and more reliable CSS animations via asynchronous animations

  • New

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

  • Changed

    Add-on extensions that are not signed by Mozilla will display a warning

  • Changed

    Smoother animation and scrolling with hardware vsync (Windows only)

  • Changed

    JPEG images use less memory when scaled and can be painted faster

  • Changed

    Sub-resources can no longer request HTTP authentication, thus protecting users from inadvertently disclosing login data

  • HTML5

    Support for new Unicode 8.0 skin tone emoji

  • HTML5

    IndexedDB transactions are now non-durable by default

  • HTML5

    Implemented AudioBufferSourceNode.detune to modulate playback rate in cents

  • Developer

    Improved Performance tools in the developer tools

  • Developer

    New rules view tooltip to tweak CSS Filter values

  • Developer

    New page ruler highlighting tool that displays lightweight horizontal and vertical rules on a page

  • Developer

    Console API messages from SharedWorker and ServiceWorker are now displayed in web console

  • Developer

    Inspector now searches across all content frames in a page

  • Developer

    Places Keywords API has been deprecated, update to the Asynchronous Keywords API

  • Developer

    Removed support for binary XPCOM components in extensions, use addon SDK "system/child_process" pipe mechanism for native binaries instead

  • Fixed

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