See what landed recently in Firefox Nightly!

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.

Firefox Nightly

March 22, 2021

Version 89.0a1, first offered to Nightly channel users on March 22, 2021

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 as well as read our Nightly Blog.


  • Say hello to a fresh new Firefox, designed to get you where you want to go even faster. We’ve redesigned and modernized the core experience to be cleaner, more inviting, and easier to use.

    Beginning in 89, you’ll notice a number of changes, including:

    • Simplified browser chrome and toolbar: Redundant or less frequently used features have been removed to focus on the most important navigation items.
    • Streamlined menus: Content has been re-organized and prioritized according to usage. We’ve reduced visual noise by removing unnecessary iconography and provided clearer labels.
    • Updated prompts: Infobars and modals have a cleaner design and clearer language.
    • Inspired new tab design: Floating tabs neatly contain information and surface cues when you need them, like visual indicators for audio controls. The rounded design of the active tab supports focus and signals the ability to easily move the tab as needed.
    • Fewer interruptions: We’ve removed unnecessary alerts and messages.
    • Cohesive, calmer visuals: Lighter iconography, a refined color palette, and more consistent styling throughout.

    This release also includes enhancements to our privacy offerings:

    • We’ve enhanced the privacy of the Firefox Browser’s Private Browsing mode with Total Cookie Protection, which confines cookies to the site where they were created, preventing companies from using cookies to track your browsing from site to site. This feature was previously available only in Firefox’s ETP Strict mode.
    • We are rolling out Version 2 of our existing SmartBlock feature, which enables a seamless web page experience that would otherwise stop working when we block trackers.
  • We keep on working on improving our PDF forms support and now support JavaScript embedded in PDF files (some PDF forms use JavaScript for validation and other interactive features). If you find any bug with this feature, please file an issue on the PDF.js repository


  • Introducing a non-native implementation of web form controls, which delivers a new modern design and some improvements to page load performance. Watch for layout bugs in web pages that make assumptions about the dimensions or styling of form controls.

    Bug 1697053

Web Platform

All Firefox Nightly downloads