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.

38.0

Firefox Release

May 12, 2015

Version 38.0, first offered to Release channel users on May 12, 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

  • New tab-based preferences

  • Ruby annotation support

  • Base for the next ESR release.

Fixed

Changed

  • autocomplete=off is no longer supported for username/password fields

  • URL parser avoids doing percent encoding when setting the Fragment part of the URL, and percent decoding when getting the Fragment in line with the URL spec

  • RegExp.prototype.source now returns "(?:)" instead of the empty string for empty regular expressions

  • Improved page load times via speculative connection warmup

Developer

  • Optimized-out variables are now visible in Debugger UI

  • XMLHttpRequest logs in the web console are now visually labelled and can be filtered separately from regular network requests

  • WebRTC now has multistream and renegotiation support

  • copy command added to console

Developer Information

HTML5

  • BroadcastChannel API implemented

  • Implemented srcset attribute and <picture> element for responsive images

  • Implemented DOM3 Events KeyboardEvent.code

  • Mac OS X: Implemented a subset of the Media Source Extensions (MSE) API to allow native HTML5 playback on YouTube

  • WebSocket now available in Web Workers

  • Implemented Encrypted Media Extensions (EME) API to support encrypted HTML5 video/audio playback (Windows Vista or later only)

  • Automatically download Adobe Primetime Content Decryption Module (CDM) for DRM playback through EME (Windows Vista or later only)

unresolved

  • Responsive images do not update when the enclosing viewport changes