How to Lock Firefox on a Mac
Firefox keeps you signed in to your accounts and restores your tabs. Its Primary Password protects saved logins, but it does not stop anyone from opening the browser itself.
Why people want to lock Firefox
For many people Firefox is where email, banking, work dashboards and social accounts all stay signed in. On an unlocked Mac, one click on the dock icon opens all of it, along with your history and bookmarks.
What doesn’t fully work
Firefox’s Primary Password is worth setting, but it protects the saved-passwords list, not the browser. Someone who opens Firefox still sees the sessions you are already signed in to. As of October 2026, Mozilla’s own community forum has open requests for a native app lock and for Touch ID support on Mac.
Closing Firefox’s windows does not stop the next person from reopening it, and Firefox can restore your previous tabs. A private window helps with history, not with the normal window one click away. A second macOS user account only works if you log out first, which is rarely realistic when you hand someone your laptop for a minute.
What actually works
Shoo! ends Firefox’s process when you lock it and starts it again only after Touch ID, Apple Watch or your private backup password succeeds. It does not draw a screen over an open browser, so nothing is visible while it is locked, and your Mac’s login password is never what unlocks it.
Two practical notes. Active downloads and half-written forms are interrupted when the process ends, so finish them first. Firefox can bring your tabs back after it reopens if “Open previous windows and tabs” is selected in its startup settings.
Try it free for 7 days — full functionality, no credit card, $17.99 once if you keep it.
Frequently asked
Can I lock Firefox with Touch ID on a Mac?
Yes. With Shoo! Firefox only opens after Touch ID succeeds, or after Apple Watch or a private backup password if your Mac has no Touch ID.
Does Firefox’s Primary Password lock the browser?
No. The Primary Password protects the saved-passwords list. Anyone who opens Firefox still reaches the sites you are signed in to.
Will I stay signed in to my accounts after unlocking Firefox?
Your sign-ins and settings are stored by Firefox itself, so they are still there when it reopens. Shoo! only controls whether the Firefox process is allowed to run.
Does Shoo! see my tabs or passwords?
No. Shoo! only controls whether the Firefox process is running. It never reads your tabs, history or saved logins.