Mozilla Firefox Nightly

Mozilla Firefox Nightly is a desktop web browser for people who want an early look at upcoming Firefox releases. Mozilla describes Nightly as a testing and development platform, so it is distinct from the regular stable Firefox release.

• Preview future Firefox browser releases.
• Use a macOS desktop application installed as Firefox Nightly.app.
• Mozilla says Nightly is unstable and updates approximately once or twice a day.
• Mozilla notes that Nightly sends data to Mozilla and sometimes its partners by default to help investigate problems and test ideas.

Install with Homebrew using brew install --cask firefox@nightly. After installation, open Firefox Nightly from your Applications folder. This cask is the Nightly build, not the stable Firefox release.

Sources: Mozilla Firefox channels · Homebrew cask