Firefox Developer Edition
Release Notes

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.

Firefox Developer Edition

March 10, 2017

Version 54.0a2, first offered to Firefox Developer Edition channel users on March 10, 2017

For more information about Developer Edition please see this MDN article.


  • Media in a new opened background tab won’t be autoplayed

  • Bookmarks created on mobile devices are now shown in "Mobile Bookmarks” folder in the drop down list from the toolbar and Bookmarks option in the menu bar in Desktop Firefox


  • Create your own custom devices in Responsive Device Mode

  • Additional changes for web developers

Get the most recent version

All Firefox Developer Edition downloads