Mozilla Firefox

Firefox is Mozilla's free, open-source web browser for everyday browsing, research, and web development. It offers independent browser technology, configurable privacy controls, extensions, and tools for organizing many tabs.

Features

• Browse with tracking protection and configurable site privacy permissions.
• Organize tabs with a sidebar, vertical tabs, groups, bookmarks, and history.
• Customize appearance and behavior with themes, extensions, and browser settings.
• Save passwords and optionally synchronize supported data across devices.
• Inspect and debug websites with integrated developer tools.
• Use separate private browsing windows; private mode does not make you anonymous to websites or network operators.

Installation and first use

Install brew install --cask firefox, then open Firefox.app from Applications. The official DMG can also be opened and Firefox dragged to Applications. Choose whether to import data from another browser and make Firefox the default browser. Review privacy, site permissions, and extension access in Settings. Sign in to a Mozilla account only if you want optional account-backed features such as synchronization. Keep Firefox updated for security fixes. The current Homebrew default download is the English-US Mac installer; other localizations can have different packages.

Mac requirements, dependencies, and conflicts

Firefox 157.0.1 officially supports macOS 10.15 or later on Intel or Apple Silicon Macs. The release's requirements page lists recommended Mac hardware of 512 MB RAM and 200 MB disk space; actual installed data, profiles, caches, and modern browsing workloads can require substantially more resources. Download size is a separate measurement. Homebrew declares no additional formula dependency or explicit minimum in depends_on, but the publisher's operating-system requirement still applies.

The cask explicitly conflicts with firefox@beta, firefox@cn, and firefox@esr. Choose the intended distribution and preserve profiles before changing channels. An existing manual Firefox.app can also occupy the same Applications path. Homebrew's optional zap cleanup removes Firefox profile and application data; back up data you want to keep. Extensions, security software, proxy settings, and site-specific permissions can affect compatibility even when they are not declared package conflicts.

Other platforms

Mozilla also provides Windows and GNU/Linux desktop builds and separate Android and iOS apps. Firefox 157.0.1 desktop requires Windows 10 or later on Windows. Linux package requirements vary by distributor; Mozilla's binary requires GTK 3.14+, glib 2.42+, suitable libstdc++, and glibc 2.17+ on x64 or 2.28+ on Arm64, among other listed libraries. This Homebrew cask installs the Mac browser, not the mobile apps. Supported site features and extension behavior can differ between platforms.

Accounts, costs, and license

Ordinary browsing requires no account and no paid subscription. A Mozilla account is optional for synchronization and related services. Optional third-party chatbot integrations or separately sold Mozilla services have their own accounts, availability, and terms; they are not included paid benefits of this free browser. Firefox's source uses Mozilla Public License 2.0 and applicable component licenses. Mozilla's trademarks, including the Firefox name and logo, are governed separately from source-code licensing.

Official references

• Firefox features
• Version-specific requirements
• Sidebar and vertical tabs
• Source repository
• Mozilla licensing