Firefox 139 is now available with custom wallpapers, link previews, and more

Firefox 139.0 is now available for download. The latest feature update for the browser includes several new features that improve translation and personalization, a new experimental link preview feature, and various bug fixes.

With Firefox 139.0, the browser can now translate extension pages that start with the moz-extension:// scheme. Mozilla says this feature has been a popular request from users, and it is now finally delivering it, allowing everyone to translate extension pages.

Next are the new customization options for the new tab page. You can now set custom wallpapers by uploading your own images for the new tab page. Also, the browser allows picking any custom color for the background. Finally, Mozilla added a new "Celestial" wallpaper category. Note that new tab page wallpaper features are rolling out gradually, but you can turn them on right away by heading to Firefox Labs.

Link Previews (on the screenshot) is a new experimental feature that you can turn on in Firefox Labs. It allows you to preview a page and get a short AI-generated summary by hovering the cursor over a link and pressing Alt + Shift.

Other changes and fixes in Firefox 139.0 include the following:

• PNG images with transparency now keep their transparency when pasted into Firefox.
• The upload performance of HTTP/3 has been significantly improved, particularly on resumed connections (QUIC 0-RTT) and high-bandwidth and high-delay connections.

• Due to recent changes in how Chrome encrypts user data on Windows, the Firefox migration wizard can no longer directly import payment methods or passwords from Chrome. However, users can still export passwords from Chrome to a CSV file and then import them into Firefox using the migration wizard or the password manager.

• The Review Checker feature is shutting down and will no longer be available after June 10, 2025.

Security fixes in Firefox 139.0 are available here. Enterprise Release Notes are available here, and Developer Information is available here.

You can update Firefox by heading to Menu > Help > About Firefox. Alternatively, get the browser from the official website or the Microsoft Store on Windows 10 and 11. Full release notes for version 139 are available here.