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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.

115.0a1 Firefox Nightly

May 8, 2023

Version 115.0a1, first offered to Nightly channel users on May 8, 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 112, Nightly users on macOS and Linux can now use FIDO2 / WebAuthn authenticators over USB. Some advanced features, such as fully passwordless logins, require a PIN to be set on the authenticator. It is expected to ship to all users in a future release.

    Bug 1814487
  • Starting with Firefox 115, Nightly users without platform support for H264 video decoding can now fallback to Cisco's OpenH264 plugin for playback.

    Bug 1832568
  • Hardware video decoding enabled for Intel GPUs on Linux.

    Bug 1777430
  • Migrating from another browser? Now you can bring over payment methods you've saved in Chrome-based browsers to Firefox.

    Bug 1393332
  • Starting with Firefox 115, Nightly users can access automated translation of web content in Firefox. Unlike cloud-based alternatives, translation is done locally in Firefox, so that the text being translated does not leave your machine.

    Bug 1831963
  • The Tab Manager dropdown now features close buttons, so you can close tabs more quickly.

    Bug 1620199
  • 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


  • Windows Magnifier now follows the text cursor correctly when the Firefox title bar is visible.

    Bug 1828295


  • On Linux, middle clicks on the new tab button will now open the xclipboard contents in the new tab. If the xclipboard content is a URL then that URL is opened, any other text is opened with your default search provider. This feature can be turned off using browser.tabs.searchclipboardfor.middleclick in about:config.

    Bug 1418462
  • For users with a Firefox Colorways built-in theme, the theme will be automatically migrated to the same theme hosted on for Firefox profiles that have disabled add-ons auto-updates. This will allow users to keep their Colorways theme when they are later removed from Firefox installer files.

    Bug 1830337
  • Undo and redo are now available in Password fields.

    Bug 1833264


  • In web development, we rely on third-party libraries which you may not be interested in while debugging. These can be ignored. Ignoring them means that breakpoints will not get hit and they are skipped during stepping.

    You can now choose to Hide ignore-listed sources in the Developer Tools source tree.

    Bug 1824703

Web Platform

  • Starting with Firefox 113, the WebTransport API is now enabled in the Nightly channel, including RFC 9297 support. It's expected to ship to release in the near future. WebTransport is expected to see widespread use for media delivery and other applications. WebTransport is built on top of QUIC/HTTP3 and provides reliable streams and reliable and unreliable datagrams.

    Bug 1818754
  • WebRTC application developers can now specify a target in milliseconds of media for the jitter buffer to hold. Altering the target value allows applications to control the tradeoff between playout delay and the risk of running out of audio or video frames due to network jitter.

    Bug 1592988
  • Change array by copy provides additional methods on Array.prototype and TypedArray.prototype to enable changes on the array by returning a new copy of it with the change.

    Bug 1811057
  • The animation-composition property is now supported, allowing a declarative way to define the composite operation used when multiple animations affect the same property simultaneously.

    Bug 1823862
  • The builtin editor now behaves similarly to other browsers with contenteditable and designMode when splitting a node, e.g. typing Enter to split a paragraph, and also when joining two nodes, e.g. typing Backspace at start of a paragraph to join the paragraph and previous one.

    When a node is split, the builtin editor creates a new node after the original one instead of before, i.e. creates the right node instead of the left node.

    Similarly, when two nodes are joined, the builtin editor deletes the latter node and moves its children to the end of the preceding node instead of deleting the former node and moving its child to start of the following node.

    Bug 1735608
  • Added the URL.canParse() function to allow easy and fast checking if URLs are valid and parseable.

    Bug 1823354

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