Firefox Monitor warns you if your online accounts were involved in a known data breach. See if your information was exposed in a data breach, learn how to take action to better protect your online accounts, and get alerted if your information appears in a new breach. You can enroll multiple email address for breach alerts from a single Firefox Account.

See if you've been part of a known breach

To see if your online accounts have been exposed in a known data breach, visit https://monitor.firefox.com/ and enter your email address. You can see what personal data was compromised and when. This basic search will surface most data breaches, but not ones that contain sensitive personal information.

Monitor your email for future breaches

If you want to receive Firefox Monitor alerts and your complete breach summary (which may contain breaches with sensitive information), create a Firefox Account:

1. Visit https://monitor.firefox.com/.
2. Select Sign up for Alerts and create a password.
3. Check your email for a verification link.

This link expires in 24 hours. After verifying your address, you’ll be able to see your complete breach summary on your Firefox Monitor dashboard. You’ll receive an alert if your email address appears in a new data breach.

Already have a Firefox Account? Sign in via https://monitor.firefox.com/ to see your summary of past breaches and automatically opt in for breach alerts. Firefox Monitor will send you an email if your information appears in a future data breach.

Monitor multiple emails for new breaches

In addition to your primary Firefox Account email, you can get breach alert sent to other email addresses. You don't have to link these email addresses to a new Firefox Account.

1. Log in to your Firefox Account via https://monitor.firefox.com/.
2. Select Manage Email Addresses to access your Monitor Preferences.
3. Enter the new email address in the email field.
4. Select Send Verification Link.
5. Check to see if a verification link was sent to that email (this link expires in 24 hours).

After verifying your address, you’ll see another breach summary on your dashboard. You’ll receive an alert if this email address appears in a new data breach.

Receive desktop browser alerts

If you use the desktop version of Firefox Quantum and visit websites in our list of breaches, you’ll receive an alert in your browser. This directs you to Firefox Monitor where you can see if your account is at risk. You will not see these alerts more than once per website.

When you browse a site with a known data breach, you’ll receive a message similar to this:

You can do any of the following from the site's webpage:

1. Select Check Firefox Monitor to see if your information was exposed when this website was breached.
2. Select the drop-down arrow next to Dismiss to dismiss all Firefox Monitor alerts on all sites.
3. Select Never show Firefox Monitor alerts.

Frequently asked questions

Have questions? Mozilla Monitor - Frequently asked questions covers many popular questions. If your question isn’t covered, go to Get Community Support to ask the community for help.