Firefox Sync lets you access data such as Bookmarks, History, Logins and Passwords, and Credit cards on other devices when you are signed in with your Mozilla account. To disable sync for sensitive data like credit cards and prevent purchases on a shared device, follow the steps below:
- In the Menu bar at the top of the screen, click and then select or , depending on your macOS version.Click the menu button and select .
in the options to the left.
- In these settings, you can choose what items to sync across devices when you signed in with your Mozilla account.
- If syncing is ON, then you're syncing the items that appear in the panel.
- Click to open the Choose What To Sync dialog.
- Uncheck the box next to Credit cards to stop syncing credit cards across devices.
- Click .
Additionally, you can disable credit card autofill to prevent Firefox from filling in your credit card information on the device where your credit card information is saved.