Firefox Sync works by storing your data on Mozilla servers and synchronizing it with your computers and devices. When you set up Sync, you enter an email address and password in order to prevent others from accessing your account. In addition, we encrypt your data with a key derived from your password in order to keep it safe on the server. This article explains what to do if you forget or lose any of this important information and are unable to access your Sync account.

I’ve forgotten my Firefox Account password — how do I reset it?

To get a new password follow these steps.

1. Click the Mozilla account icon on the Firefox toolbar.

   

2. Click Turn on Sync.
3. On the Sign in page, click Forgot password? Firefox will send you a reset email.
4. Follow the instructions in your reset email to change your password.
5. After signing in with your new password, remember to update your password on each of your synced devices.

I’ve forgotten, or don't have access to, my Firefox Account email address

Unfortunately there's no way to change or recover the email address associated with a Sync account. You would need to create a new account following the steps described in How do I set up Sync on my computer?