Firefox 137.0

Tab groups begin rolling out today! Stay productive and organized with less effort by grouping related tabs together. One simple way to create a group is to drag a tab onto another, pause until you see a highlight, then drop to create the group. Groups can be named, color-coded, and are always saved. You can close a group and reopen it later. This feature is part of a progressive roll out. What is a progressive roll out? Certain new Firefox features are released gradually. This means some users will see the feature before everyone does. This approach helps to get early feedback to catch bugs and improve behavior quickly, meaning more Firefox users overall have a better experience.

Firefox Address Bar Refresh 2025 - new ways to search for things new, previously viewed, and more - all from the address bar: Features Unified Search Button : A new, easy-to-access button in the address bar helps you switch between search engines and search modes with ease. This feature brings the simplicity of mobile Firefox to your desktop experience. Search Term Persistence : Now when you refine a search in the address bar, the original term sticks around, making it easier to adjust your queries and find exactly what you're looking for. Secondary Action Buttons : Suggestions for common Firefox features. Contextual Search Mode : Firefox detects if you are on a page that has search capability and offers that option for you to directly search with the page engine from the address bar. Use this option at least 2 times and Firefox will suggest adding the search engine to your Firefox. Contextual Search Engine Options : Use a Contextual Search mode option at least 2 times and Firefox will suggest adding the search engine to your Firefox so that it’s always available to you. Intuitive Search Keywords : You can access various address bar search modes with convenient and descriptive keywords (e.g. @bookmarks,@tabs,@history, @actions). This feature is part of a progressive roll out. What is a progressive roll out? Certain new Firefox features are released gradually. This means some users will see the feature before everyone does. This approach helps to get early feedback to catch bugs and improve behavior quickly, meaning more Firefox users overall have a better experience.

Firefox now identifies all links in PDFs and turns them into hyperlinks.

Support HEVC playback on Linux.

Now you can sign PDFs without leaving Firefox. Save your signatures to re-use later. This feature is part of a progressive roll out. What is a progressive roll out? Certain new Firefox features are released gradually. This means some users will see the feature before everyone does. This approach helps to get early feedback to catch bugs and improve behavior quickly, meaning more Firefox users overall have a better experience.

You can now use the Firefox address bar as a calculator. Simply type an arithmetic expression and view the result in the address bar drop-down. Clicking on this result will copy it to your clipboard. This feature is part of a progressive roll out. What is a progressive roll out? Certain new Firefox features are released gradually. This means some users will see the feature before everyone does. This approach helps to get early feedback to catch bugs and improve behavior quickly, meaning more Firefox users overall have a better experience.

We are investigating an increase in crashes for Windows users with Qihoo 360 security software. (Fixed in 137.0.1)

Due to recent changes in Chrome on Windows, some users might find that the Firefox migration wizard no longer successfully imports passwords from Chrome or Chrome-based browsers. As a workaround, you can export your passwords as a CSV file from Chrome and then import them into Firefox using either the migration wizard or the Firefox password manager.

Various security fixes .

You can find information about policy updates and enterprise specific bug fixes in the Firefox for Enterprise 137 Release Notes .

Developer Information

In the Inspector Fonts panel, we now display fonts metadata, like the font version, designer, vendor, license…

The Network panel now allows overriding network request responses with local files.

With the release of Firefox 137, we are pleased to welcome the developers who contributed their first code change to Firefox in this release, 17 of whom were brand new volunteers! Please join us in thanking each of these diligent and enthusiastic individuals, and take a look at their contributions: [:anutrix]: 1727389 , 1948502

Adds commands.openShortcutSettings that opens the Manage Extension Shortcuts page of Manage Your Extensions ( about:addons ) and, if the extension has shortcuts, scrolls to and highlights the extension's shortcut key options. ( Firefox bug 1538451 )

The 10 MB quota for data stored by the storage.session API is now enforced. ( Firefox bug 1915688 )

Temporal API (Nightly release): is now enabled in Firefox Nightly by default. The Temporal object aims to simplify working with dates and times in various scenarios, with built-in time zone and calendar representations. ( Firefox bug 1946823 ).

Support for the SVG 2 path API is now available.

Support for the hyphenate-limit-chars property is now available. This property enables authors to have greater control over the use of automatic hyphenation.

The hyphenate-limit-chars CSS property provides you with fine-grained control over hyphenation in text. It is used to specify the minimum word length for hyphenation as well as the number of characters before and after the hyphen. ( Firefox bug 1947183 ).

The text-decoration-line CSS property now accepts the values spelling-error and grammar-error . These values use the browser's styling for spelling and grammar errors and disregard the other properties in the text-decoration shorthand. ( Firefox bug 1950844 ).

The Math.sumPrecise() static method is now supported. This takes an iterable (such as an Array ) of numbers and returns their sum. It is more precise than summing the numbers in a loop because it avoids floating point precision loss in intermediate results. ( Firefox bug 1943120 ).

The Atomics.pause() static method is now supported. This method provides a hint to the CPU that the current thread is in a spinlock while waiting on access to a shared resource. The system can then reduce the resources allocated to the core (such as power) or thread, without yielding the current thread. ( Firefox bug 1937805 ).

The getPathData() , setPathData() , and getPathSegmentAtLength() methods of the SVGPathElement interface are now supported. These methods provide a convenient way to work with SVG path data instead of parsing raw string data. ( Firefox bug 1945312 ).

HEVC (H.265) is now hardware enabled on Android, and hardware and software enabled on Linux. This adds to existing hardware and software support on Windows and macOS. ( Firefox bug 1950032 ).

The following non-standard events are now deprecated and proposed for removal: afterscriptexecute and beforescriptexecute in Document , and afterscriptexecute , and beforescriptexecute in Element . A console warning is displayed when they are used. ( Firefox bug 1949373 ).

Input sources of type mouse and touch now support fractional numbers for x and y positions for the pointerMove action ( Firefox bug 1946774 ).

Implemented new webExtension.install ( Firefox bug 1934551 ) and webExtension.uninstall ( Firefox bug 1934553 ) commands, enabling clients to install and uninstall web extensions in the browser.

Added support for userContexts argument to sessions.subscribe command, which allows clients subscribing to a list of user contexts (also known as Firefox containers) ( Firefox bug 1938604 ).

script.addPreloadScript command is updated to throw an invalid argument error when both contexts and userContexts arguments are provided ( Firefox bug 1945554 ).

browsingContext.navigate command will not return immediately anymore when wait argument equals none and beforeunload prompt opens. That's the first step of updating the logic behind wait argument equals none ( Firefox bug 1948700 ).

From now on, a javascript error from a syntax error raised by script evaluation will contain line and column number ( Firefox bug 1865146 ).

Performing actions with async events enabled will not fail anymore with a Cyclic object value error message ( Firefox bug 1947112 ). Async events were enabled since Firefox 135. See more details in the release notes .