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Firefox Nightly
Release Notes

Release Notes tell you what’s new in Firefox. As always, we welcome your feedback. You can also file a bug in Bugzilla or see the system requirements of this release.

119.0a1 Firefox Nightly

August 28, 2023

Version 119.0a1, first offered to Nightly channel users on August 28, 2023

Firefox Nightly gets updated every day and as a consequence, the release notes for the Nightly channel are updated continuously to reflect features that have reached sufficient maturity to benefit from community feedback and bug reports.

Warning: Features listed here may or may not make a final release of Firefox.

In addition to these release notes, you can follow ongoing development on our @FirefoxNightly Twitter account, our Mastodon account as well as read our Nightly Blog.

You can interact with other Firefox Nightly users and give your feedback to Mozilla staff in the Nightly Matrix room on


  • Starting with Firefox 115, Nightly supports a new “Copy Link Without Site Tracking” context menu action which prevents disclosure of identifying or sensitive information by removing superfluous query and tracking parameters from the copied links.

    Bug 1823332
  • Starting with Firefox 117, recently closed tabs now persist between sessions for Nightly users that don't have automatic session restore enabled. Manually restoring a previous session will continue to reopen any previously open tabs or windows.

    Bug 1820660
  • Starting with Firefox 117, Nightly builds now support adding images when editing PDFs in addition to adding text and drawing.

    Bug 1843054
  • Starting with Firefox 118, Nightly now supports UI setting that enables the user to opt-in into GPC, a privacy signal that tells the websites that the user doesn’t want to be tracked and doesn’t want their data to be sold.

    Bug 1830623
  • Firefox View now includes more content:

    • You can now see all open tabs from all windows.
    • If you sync open tabs then you will now see all tabs from other devices.
    • Browsing history is now listed and you can sort by date or by site.
    • As before, recently closed tabs are also listed in Firefox View.
    Bug 1847981
  • If the relevant Windows mouse properties system setting is enabled, the mouse pointer will disappear while typing.

    Bug 1757463
  • If you're migrating your data from Chrome, Firefox now offers the ability to import some of your extensions as well.

    Bug 1853926
  • Media sniffing is now disabled for top-level documents served as type application/octet-stream. Allowing these files to be downloaded instead of attempting playback.

    Bug 1828441


Web Platform

  • Starting with Firefox 117, partial support for the custom highlight API is now available in Nightly builds, allowing web developers to give ranges an appearance.

    Bug 1840818
  • ARIA reflection for simple attributes and default Accessibility Semantics for Custom Elements are now supported. Note that this includes boolean, enum, number, and string attributes, but not attributes that reference other elements.

    Bug 1785412
  • Starting with Firefox 119, the :has() selector is now available in nightly builds. This allows authors to match elements that has, or "anchors", at least one element matching its relative selector.

    Bug 1853701
  • credentialless is now supported in Cross-Origin-Embedder-Policy.

    Bug 1851467

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All Firefox Nightly downloads