Firefox Primary Password adds one extra lock to the passwords stored inside Firefox. Without it, someone using your unlocked computer may be able to open Firefox saved logins and reveal passwords. With it enabled, Firefox asks for the Primary Password before saved logins can be accessed during that session.
Does this affect you?
Use this for Firefox on Windows, Mac, or Linux if you save passwords in Firefox and want extra protection from someone sitting at your computer. Older guides may call this Master Password; Mozilla renamed it Primary Password in 2020.
Set a Primary Password
It takes less than a minute.
- Click the Firefox menu button.
- Open Settings.
- Choose Privacy & Security.
- Scroll to Logins and Passwords.
- Check Use a Primary Password.
- Enter the new password twice and confirm.
Firefox asks for the Primary Password the first time in a session that something needs saved-login access. It does not ask before every single autofill after that initial unlock.
Change or remove your Primary Password
You need the current Primary Password to make either change normally.
- Open Settings > Privacy & Security > Logins and Passwords.
- Click Change Primary Password.
- Enter the current password.
- Type the new one twice to change it, or uncheck Use a Primary Password to remove it.
- Confirm the change.
More control
It protects Firefox saved logins only
The Primary Password is separate from your Windows or Mac account password and separate from your Firefox Account used for Sync. It does not lock the whole browser or the operating system.
It does not sign you out of open sites
If a website is already signed in inside an open tab, Primary Password does not lock that live session. It protects new attempts to read saved login entries, such as opening the saved password list or filling a login form.
Forgotten password resets are destructive
If you forget the Primary Password, Firefox can reset it, but the reset removes saved logins rather than recovering them. Use the Forgot password path only when you accept losing stored Firefox passwords.
Sources
- Mozilla Support – Use a Primary Password to protect stored logins and passwords (2025)
- Mozilla Support – Change, forget or reset your Firefox Primary Password (2025)
- Mozilla Support – Password manager: remember, delete, change and import saved passwords in Firefox (2025)