Firefox Sync allows you to sync your bookmarks, logins and passwords, browsing history, tab settings and other items across various devices. See How do I set up Sync on my computer? to learn more about how to turn on Sync.

You can disable Sync, if you you’d like, to avoid syncing your data across certain devices when creating or signing into a Firefox Account. You'll remain signed in to your account even after Sync has been disabled, unless you decide to sign out. You can also disable Sync for devices that have been synced previously. For additional information, see Remove a synced device from your Mozilla account.

Disable Sync for previously synced devices

To disable Sync for previously synced devices:

1. Click the Firefox Account icon in the toolbar.

   

2. Select Sync Settings from the drop-down menu.

   

   The Sync panel of your Firefox Settings page will open.

3. Click the Change… button in the Syncing: ON subsection.
   The Choose What To Sync pop-up will open.

   

4. Click Disconnect…. A confirmation prompt will appear.

   

5. Click the Disconnect… button in the Disconnect Sync? prompt.

Firefox will stop syncing your account but won’t delete any data or settings. The Sync panel of your Firefox Settings page will now show Syncing: OFF.

Disable Sync from an existing Firefox Account for a new device

To disable Sync when signing in to your Firefox Account on a new device:

1. Sign in to your Firefox Sync account.
2. Click Don’t sync this device.
   A confirmation message will display when your settings are applied.
3. Sign in with the appropriate credentials.