What's new in Firefox Nightly for Developers 139.0a1
From version 5.2.0:
* Sort Logins
* Streamline Bookmarks/History access
* Improved QR code scanning
* Stability and bugfixes
About Firefox Nightly for Developers 139.0a1
Warning: Nightly is an unstable testing and development platform. By default, Firefox Nightly automatically sends data to Mozilla — and sometimes our partners — to help us handle problems and try ideas. Learn what is shared: www.mozilla.org/en-US/privacy/firefox/#pre-release
Firefox Nightly gets updated every day and is designed to showcase the more experimental builds of Firefox. The Nightly channel allows users to experience the newest Firefox innovations in an unstable environment and provide feedback on features and performance to help determine what makes the final release.
Found a bug? Report it at: bugzilla.mozilla.org/enter_bug.cgi?product=Fenix
Want to know more about the permissions Firefox requests?: mzl.la/Permissions
See our list of supported devices and latest minimum system requirements at: www.mozilla.org/firefox/mobile/platforms/
Mozilla marketing: In order to understand the performance of certain Mozilla marketing campaigns, Firefox sends data, including a Google advertising ID, IP address, timestamp, country, language/locale, operating system, app version, to our third party vendor. Learn more by reading our Privacy Notice here: www.mozilla.org/privacy/firefox/
Take a browse on the wild side. Be among the first to explore future releases.
Download Firefox Nightly for Developers 139.0a1
This release comes in several variants (we currently have 27). Consult our handy FAQ to see which download is right for you.
Version:147.0a1
Uploaded:December 3, 2025 at 1:30PM UTC
File size:55.6 MB
Downloads:1,467
Version:146.0a1
Uploaded:November 10, 2025 at 2:18PM UTC
File size:58.28 MB
Downloads:2,139
Version:145.0a1
Uploaded:October 13, 2025 at 8:09AM UTC
File size:58.17 MB
Downloads:1,226
Version:144.0a1
Uploaded:September 14, 2025 at 5:33PM UTC
File size:56.07 MB
Downloads:1,068
Version:143.0a1
Uploaded:August 18, 2025 at 9:16PM UTC
File size:55.76 MB
Downloads:1,074
Version:142.0a1
Uploaded:July 22, 2025 at 3:31AM UTC
File size:54.73 MB
Downloads:1,073
Version:141.0a1
Uploaded:June 23, 2025 at 5:45PM UTC
File size:54.02 MB
Downloads:902
Version:140.0a1
Uploaded:May 27, 2025 at 10:48PM UTC
File size:53.5 MB
Downloads:1,103
Version:139.0a1
Uploaded:April 28, 2025 at 5:45PM UTC
File size:52.36 MB
Downloads:1,540
Version:138.0a1
Uploaded:April 1, 2025 at 4:08PM UTC
File size:51.65 MB
Downloads:1,266





































