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Password Breach Checker

Password Breach Checker

Check if your password has appeared in known data breaches.

🔒 Your password never leaves your browser. Only the first 5 characters of its SHA-1 hash are sent to the HIBP API (k-anonymity model).

Powered by Have I Been Pwned

About this tool

Password Breach Checker runs entirely in your browser on DevTools — no signup, no upload.

What this tool does not do

  • Password Breach Checker is a free in-browser utility, not a hosted API, and keeps no server-side history.

How to use this tool

  1. Using Password Breach Checker

    Open Password Breach Checker, enter or paste your input, and copy the result.

Related guides

Measuring Password Strength with Entropy and Checking Known Breaches

How password entropy is calculated in bits, zxcvbn dictionary matching, and k-Anonymity privacy in Have I Been Pwned breach checks.

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