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Password leak check

Check if your password has appeared in known data breaches. Powered by Have I Been Pwned. Your password is never sent — only a hash prefix is used.

Privacy

Your password is never sent anywhere. It is hashed with SHA-1 in your browser; only the first 5 characters of the hash are used to query Have I Been Pwned. This is the k-anonymity method used by 1Password, Firefox, and others.

About this check

  • Uses the Have I Been Pwned (haveibeenpwned.com) Pwned Passwords API
  • Checks against 600+ million passwords from known data breaches
  • k-Anonymity: only a hash prefix is sent; your password never leaves your device