Using Firefox on Mac: What's Different from Safari and Chrome

Firefox on Mac works well. A few things behave differently from Safari and Chrome. Here's what to know.

Native macOS Integration

What Safari does better:

• Keychain integration: Safari syncs passwords directly with iCloud Keychain; Firefox has its own password manager
• System proxy settings: Safari uses macOS system network settings seamlessly; Firefox has its own proxy configuration
• Native scrolling: Safari's scrolling physics match macOS system scrolling exactly; Firefox is close but slightly different
• Reader Mode: Safari's Reader Mode is slightly more polished with font options like New York
• Apple Watch unlock: Safari supports Apple Watch unlocking; Firefox does not

What Firefox matches:

• Picture-in-Picture video: works in Firefox, same keyboard shortcut territory
• Dark mode via prefers-color-scheme: responds to macOS dark mode setting
• Touch bar (older MacBooks): Firefox has basic Touch bar support

Extensions Ecosystem

Safari uses the App Store for extensions. Firefox uses AMO (addons.mozilla.org). Both have:

• uBlock Origin (ad blocker)
• 1Password / Bitwarden
• Video downloaders and utilities

Firefox's extension library is larger overall. Safari's extensions are Mac-native App Store apps that often have better iOS/iPhone sync through the same purchase.

The key difference: Firefox still supports Manifest V2 extensions. Chrome (and therefore most cross-browser extensions) is moving to MV3 which limits ad blocker capabilities. Safari uses its own WebExtension API. Firefox MV2 support means full-featured ad blocking that Chrome is phasing out.

Performance on Apple Silicon

Firefox has native Apple Silicon support (arm64) — download from mozilla.org or install via Homebrew:

brew install --cask firefox

Firefox on M1/M2/M3 Mac runs natively and is fast. Memory usage is generally lower than Chrome; comparable to Safari on most workloads.

iCloud Keychain vs Firefox Password Manager

Firefox's built-in password manager is separate from iCloud Keychain. If you use iCloud Keychain extensively (autofill across iPhone, iPad, Mac), switching browsers means either:

1. Exporting passwords from Keychain and importing to Firefox Password Manager
2. Using a cross-platform password manager (1Password, Bitwarden) that works in both

If you use Safari on iPhone, importing to Firefox on Mac means passwords won't auto-fill on iOS unless you also install Firefox for iOS and sync through a Firefox account.

Sync With iPhone

Firefox for iOS exists and syncs via Firefox account:

• Bookmarks
• History
• Open tabs (send-to-device for individual tabs)
• Passwords (Firefox Password Manager)

The Send-to-Device feature lets you push a tab from Mac Firefox to iPhone Firefox directly from the address bar menu.

Features Mac Firefox Users Appreciate

Multi-Account Containers: Isolate cookies by container. Safari's privacy mode is session-based and less flexible; Firefox containers let you stay persistently logged into separate accounts in different containers.

Tab session management: Firefox's built-in session restore handles crashes and restarts. Extensions like Tab Manager & Session Saver add named session snapshots for deliberate context switching — useful on a Mac where you might have multiple spaces/desktops with different work contexts.

Dark mode enforcement: macOS dark mode + Firefox's enhanced tracking protection + NightOwl for sites that ignore system dark mode gives a consistent dark environment across almost everything.

The Honest Trade-Off

Safari on Mac has unmatched system integration and the best power efficiency (biggest impact on battery life with heavy use). If you primarily use Apple's ecosystem and iCloud Keychain, Safari has real advantages.

Firefox on Mac offers better extension capability (especially ad blocking), more fine-grained privacy controls, and cross-platform sync if you use non-Apple devices. The performance gap between Safari and Firefox has narrowed significantly on Apple Silicon.