Firefox Nightly is a developmental channel for new Mozilla Firefox releases.

Please note that Firefox Preview has transitioned to Firefox Nightly.

Download the release version of Firefox.

Firefox Nightly is designed to showcase the more experimental builds of Firefox. The Nightly channel allows users to experience the newest Firefox innovations in an unstable environment and provide feedback on features and performance to help determine what makes the final release.

Found a bug? Report it at Github.

Firefox Nightly automatically sends feedback to Mozilla: https://www.mozilla.org/privacy/firefox/#telemetry

Want to know more about the permissions Firefox requests?
https://mzl.la/Permissions

See our list of supported devices and latest minimum system requirements at
https://www.mozilla.org/firefox/mobile/platforms/

Mozilla marketing: In order to understand the performance of certain Mozilla marketing campaigns Firefox sends data including a Google advertising ID IP address timestamp country language/locale operating system app version to our third party vendor. Learn more by reading our Privacy Notice here:
https://www.mozilla.org/privacy/firefox/