Firefox 152 release notes for developers (Beta)
This article provides information about the changes in Firefox 152 that affect developers. Firefox 152 is the current Beta version of Firefox and ships on June 16, 2026.
Note: The release notes for this Firefox version are still a work in progress.
Changes for web developers
APIs
DOM
- The
actionsread-only property and themaxActionsstatic read-only property of theNotificationinterface are supported. These contain the notification actions set withServiceWorkerRegistration.showNotification(), and the platform-dependent maximum number of actions that can be set for a notification, respectively. (Firefox bug 1959931).
Media, WebRTC, and Web Audio
- The
recieveTimeproperty is now included in the metadata returned fromRTCEncodedVideoFrame.getMetadata()andRTCEncodedAudioFrame.getMetadata(), and can be passed to theRTCEncodedVideoFrame()andRTCEncodedAudioFrame()constructors as a property in theoptionsparameter. (Firefox bug 2033420).
Changes for add-on developers
-
The ability of extensions to dynamically execute code in their
moz-extension:documents withtabs.executeScript,tabs.insertCSS,tabs.removeCSS,scripting.executeScript,scripting.insertCSS, andscripting.removeCSShas been removed. This feature was deprecated in Firefox 149. (Firefox bug 2015559)As an alternative, an extension can run code in its documents dynamically by registering a
runtime.onMessagelistener in the document's script, then sending a message to trigger execution of the required code.
Experimental web features
These features are shipping in Firefox 152 but are disabled by default.
To experiment with them, search for the appropriate preference on the about:config page and set it to true.
You can find more such features on the Experimental features page.