Password Leak Monitor

A browser addon that automatically monitors all passwords used and alerts you if it has been included in any data breaches.

Download for Firefox

Also check out the password-leak JavaScript library!

How is this safe?

Your passwords are NEVER transmitted to any other system. This addon makes use of the Have I Been Pwned API, which implements a k-Anonymity Model so your password can be checked without ever having to give your password to any other party.

How does it work?

It's a fairly simple extension: for every password you enter, a call is made to Have I Been Pwned with the first five characters of your hashed password. A list of potential matches is returned, and the addon determines if your hashed password matches any of the compromised hashes.