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What's new in Firefox Nightly for Developers 149.0a1
From version 5.2.0:
* Sort Logins
* Streamline Bookmarks/History access
* Improved QR code scanning
* Stability and bugfixes
About Firefox Nightly for Developers 149.0a1
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
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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/
BILLIONAIRE FREE FOR 20+ YEARS
The Firefox browser was created in 2004 by Mozilla as a faster, more private browser with more customizable features than web browsers like Internet Explorer. Today, we are still not-for-profit, still not owned by any billionaires and still working to make the internet — and the time you spend on it — better. To learn more about Mozilla, please go to www.mozilla.org.
LEARN MORE
- Terms of Use: www.mozilla.org/about/legal/terms/firefox/
- Privacy Notice: www.mozilla.org/privacy/firefox
- Latest news: blog.mozilla.org
Take a browse on the wild side. Be among the first to explore future releases.
Download Firefox Nightly for Developers 149.0a1
This release comes in several variants (we currently have 22). Consult our handy FAQ to see which download is right for you.
Version:149.0a1
Uploaded:January 26, 2026 at 2:01PM UTC
File size:57.05 MB
Downloads:479
Version:148.0a1
Uploaded:January 12, 2026 at 2:44PM UTC
File size:56.34 MB
Downloads:1,360
Version:147.0a1
Uploaded:December 8, 2025 at 1:51PM UTC
File size:55.6 MB
Downloads:1,755
Version:146.0a1
Uploaded:November 10, 2025 at 2:18PM UTC
File size:58.28 MB
Downloads:2,186
Version:145.0a1
Uploaded:October 13, 2025 at 8:09AM UTC
File size:58.17 MB
Downloads:1,233
Version:144.0a1
Uploaded:September 14, 2025 at 5:33PM UTC
File size:56.07 MB
Downloads:1,171
Version:143.0a1
Uploaded:August 18, 2025 at 9:16PM UTC
File size:55.76 MB
Downloads:1,115
Version:142.0a1
Uploaded:July 22, 2025 at 3:31AM UTC
File size:54.73 MB
Downloads:1,085
Version:141.0a1
Uploaded:June 23, 2025 at 5:45PM UTC
File size:54.02 MB
Downloads:905
Version:140.0a1
Uploaded:May 27, 2025 at 10:48PM UTC
File size:53.5 MB
Downloads:1,119
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