Set or Change the Primary Password in Firefox (Formerly Master Password)

Firefox's Primary Password (formerly called Master Password) encrypts your saved logins locally and gates access to them once per browser session. Use it to lock down stored credentials from anyone who can open your Firefox profile.

Firefox does not turn this feature on by default, so you have to enable it yourself. You can do this from the Logins and Passwords page or from Settings under Privacy and Security. Changing an existing password uses the same path. Both methods are below, plus what to do if you forget it.

In this guide, I have covered:

What the Firefox Primary Password Does Before You Set or Change It

You have saved logins in Firefox, and you would rather not leave them readable by anyone who opens your profile. Before you set or change the primary password in Firefox, it helps to know exactly what the feature protects. The Primary Password (formerly called Master Password) is the local encryption key that protects those saved logins. When you set one, Firefox encrypts the usernames and passwords stored in your profile and only unlocks them after you type the password.

Firefox prompts for it once per browser session, the first time the browser needs to read or autofill a saved credential. After that, the unlock is cached until you quit Firefox and start it again. Firefox does not enable this feature by default. If you want protection against anyone opening your profile file or your browser while you are away, turn it on yourself.

For the official Mozilla documentation, see the Primary Password support page on support.mozilla.org.

The Primary Password is a desktop-only Firefox feature. Firefox on Android and iOS do not expose this option, because mobile builds rely on the operating system’s screen lock and biometric protection instead. The steps below apply to Firefox on Windows, macOS, and Linux only.

Set a Primary Password From the Logins and Passwords Page

If you already use Firefox’s built-in password manager, this is the fastest route. The toggle sits right next to where you manage saved logins.

1. Click the hamburger menu at the top right of Firefox.
2. Choose Logins and Passwords.
3. In the upper right of the Logins and Passwords page, click the ellipsis button and select Options.
4. In the Logins and Passwords section, tick Use a Primary Password.
5. In the Change Primary Password dialog, enter your new password, confirm it, then click OK.

Firefox may ask you to retype the password once more to confirm. After that, your saved logins are encrypted at rest in this profile. Firefox prompts for the Primary Password the next time it needs to fill or reveal a credential.

Set a Primary Password From Privacy and Security Settings

If you prefer to work from Firefox’s main settings panel, the same toggle is also reachable through Privacy and Security.

1. Click the hamburger menu at the top right of Firefox and choose Settings.
2. In the left sidebar, select Privacy & Security.
3. Scroll down to the Logins and Passwords section.
4. Tick Use a Primary Password.
5. In the Change Primary Password dialog, type the password, confirm it, then click OK.

If Firefox already has a Primary Password set on this profile, the row will read Change Primary Password… instead. Click it to open the same dialog and update the existing password.

Change an Existing Primary Password

If you already set a Primary Password and need to replace it, the process uses the same screen as the original setup. The dialog now also asks for your current password so Firefox can verify you have permission.

1. Open the hamburger menu , then Settings, then Privacy & Security.
2. Scroll to the Logins and Passwords section.
3. Click Change Primary Password….
4. Enter your current password, then the new password twice for confirmation.
5. Click OK to save.

Pick a strong, unique password that you can actually remember. Firefox will not let you autofill or reveal any saved login while the new password is being saved, so check the entry before you click OK.

ALERT: If you forget your Primary Password, there is no recovery option. Firefox cannot decrypt your saved logins without it. You would have to visit each site individually and reset your password there. Removing the Primary Password on Firefox will not unlock the existing entries either, because Firefox discards the encryption key the moment you remove it. You can read more about this limitation on Mozilla’s Primary Password support page.

Remove the Primary Password

If you no longer want a Primary Password on this profile, Firefox lets you remove it from the same Logins and Passwords section.

1. Open the hamburger menu , then Settings, then Privacy & Security.
2. Scroll to Logins and Passwords.
3. Untick Use a Primary Password.
4. Enter the current password when Firefox prompts you and click OK.

After you remove it, your saved logins remain in Firefox but are no longer encrypted by a Primary Password. Anyone who can open the profile can read them. Only remove the Primary Password if you trust everyone who can open that Firefox profile.

Firefox Mobile and the Primary Password

You won’t find the Primary Password option in Firefox for Android or Firefox for iOS. Mozilla’s mobile apps do not store passwords in an encrypted local store the way the desktop browser does.

Instead, mobile Firefox relies on the device’s screen lock, fingerprint, or face recognition to gate access to the browser. To change that protection, edit the screen lock settings in your phone’s system settings rather than anything inside Firefox.

Other mobile browsers handle password-related privacy differently. If you’re checking those settings on a phone, see how to enable privacy and security settings in Edge on Android, tighten Chrome privacy settings on Android, or manage Safari privacy settings on iPhone and iPad.

For desktop profiles, use the Logins and Passwords page or Settings path to set, change, or remove the local lock. Once it is on, Firefox asks for it only when a saved login is needed.

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