Password Leak Check

Type or paste the password and this tool checks it against Have I Been Pwned's Pwned Passwords database of over half a billion passwords exposed in real data breaches. If it appears, you see how many times, a sign it is publicly known and used in attacks. It does this without ever sending your actual password, using a privacy technique called k-anonymity.

Yes, because of how the check works. Your password is scrambled into a fingerprint (a SHA-1 hash) inside your browser, and only the first five characters of that fingerprint are sent to the breach service. Those five characters match thousands of different passwords, so the service cannot tell which one is yours, and your real password never leaves your device. As a general habit, though, retire any password you have typed anywhere you are unsure about.

K-anonymity is a way to look something up without revealing what you are looking for. Instead of sending your password's full fingerprint, your browser sends only a short prefix of it. The server returns every leaked password sharing that prefix, thousands of them, and your browser finds the match locally. The server learns only the prefix, never your password or its full hash.

Change it immediately everywhere you have used it, starting with your most important accounts like email and banking, and never use it again. Then move to a unique password for every account so a single leak cannot unlock the rest, use a password manager to handle them, and turn on two-factor authentication so a leaked password alone is not enough to get in.

It means this exact password has not appeared in the breaches this database tracks, which is good, but it is not a guarantee. A password can be unique and still be weak or easy to guess, and databases do not contain every breach. Aim for long, random, unique passwords or passphrases regardless of the result.

No. It checks the password itself, not any specific account. To see whether your email address has appeared in known breaches, use the email search on the Have I Been Pwned website. This tool focuses on the password so it can do the check privately, in your browser.

Yes, free with no signup and unlimited.