Mozilla Firefox 139 is rolling out with translation, customization features & more

Mozilla Firefox 139 is now rolling out with several useful features that boost personalization, translation, and performance. The update also introduces a new experimental tool called Link Previews.

What’s new in Mozilla Firefox 139

The latest version lets you translate extension pages that use the moz-extension:// address. This is something users have requested for a while, and Mozilla’s now made it possible.

You’ll also find more ways to personalize the new tab page. Mozilla Firefox 139 lets you upload your own wallpapers and pick any custom background color.

There’s a new built-in “Celestial” wallpaper set, too. These features are gradually rolling out, but you can enable them early through Firefox Labs.

Also read: Firefox Finally Lets You Remove the Extensions Button from the Toolbar

Link Previews and other changes

Link Previews is an experimental feature you can turn on in Firefox Labs. Once it’s enabled, you can hover your mouse over any link and press Alt + Shift to get an AI-generated summary of the page. It’s designed to save you time before clicking through a link while browsing the web in version 139 of the Mozilla Firefox browser.

Firefox 139 update also improves how the browser handles PNG transparency when pasting images. Upload performance is better with HTTP/3 connections, especially on high-latency or resumed transfers using QUIC 0-RTT.

There’s a limitation, though. Firefox can no longer directly import Chrome passwords or payment data due to Chrome’s new encryption methods on Windows. Still, you can export Chrome passwords to a CSV and import them manually. Mozilla has also confirmed that its Review Checker tool will be discontinued after June 10, 2025.

Also read: Firefox Update Will Prompt Users to Accept Terms of Use at Startup with Opt-Out options

You can get the update by going to Menu > Help > About Firefox, or downloading it from Mozilla’s site or the Microsoft Store.