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Email Breach Checker

Check if your email address has appeared in known data breaches. Powered by the HaveIBeenPwned public dataset.

🔒 Privacy-first: We use the k-Anonymity model — only the first 5 characters of a SHA-1 hash of your email are sent to the API. Your full email address is never transmitted.
Results come from the HaveIBeenPwned public API (breach data only, no paste data). An API key is not required for breach lookups.

What is a Data Breach?

A data breach occurs when hackers gain unauthorized access to a website or service's database and steal user information such as email addresses, passwords, phone numbers, and credit card details. The stolen data is often sold on the dark web or published publicly. Checking if your email has been part of a breach helps you identify which services you should change your password for.

What To Do If You're Pwned

  1. Change your password immediately for the breached service.
  2. Check if you reuse the same password on other sites — change those too.
  3. Enable two-factor authentication (2FA) on all important accounts.
  4. Consider using a password manager like Bitwarden or 1Password to generate unique passwords.
  5. Monitor your email for phishing attempts that may use your breached data.
  6. Check your credit report if financial information was exposed.

Frequently Asked Questions

No. We use the k-Anonymity model: your email is hashed with SHA-1 client-side, only the first 5 characters of that hash are sent to the HIBP API, and the response contains all possible matching hashes. The comparison is done entirely in your browser.

All breach data is sourced from the HaveIBeenPwned (HIBP) project, founded by security researcher Troy Hunt. HIBP aggregates data from known public data breaches and makes it searchable. As of 2024, HIBP contains over 12 billion breached accounts.

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