Firefox 150 release notes for developers (Nightly)

This article provides information about the changes in Firefox 150 that affect developers. Firefox 150 is the current Nightly version of Firefox and ships on April 21, 2026.

[!NOTE] The release notes for this Firefox version are still a work in progress.

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Changes for web developers

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Changes for add-on developers

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Experimental web features

These features are shipping in Firefox 150 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.