--- title: "Password Breach Checker" description: "Check if a password appears in known data breaches. This page hashes it in your browser and sends only 5 characters of the SHA-1 to Have I Been Pwned." url: https://findutils.com/security/password-breach-checker/ category: security --- # Password Breach Checker Check if a password appears in known data breaches. This page hashes it in your browser and sends only 5 characters of the SHA-1 to Have I Been Pwned. **Use this tool:** [Password Breach Checker](https://findutils.com/security/password-breach-checker/) ## Programmatic access - REST id `password-breach-checker`: POST https://api.findutils.com/api/tools/password-breach-checker/execute (reference: https://findutils.com/api/password-breach-checker/) - MCP tool `password_breach_checker` on https://mcp.findutils.com (reference: https://findutils.com/mcp/password-breach-checker/) ## Why Check for Breached Passwords? Data breaches expose millions of passwords every year. Attackers use these leaked passwords in credential stuffing attacks. If your password has been breached, you should change it immediately on all accounts where you use it. ## Password Security Tips - Use a unique password for every account so that one breach does not compromise all your logins. - Aim for passwords that are at least 12 characters long and include uppercase letters, lowercase letters, numbers, and symbols. - Enable two-factor authentication on every service that supports it, especially email and banking. - Use a reputable password manager to generate and store complex passwords instead of trying to memorize them. - Run a breach check on your most important passwords at least once every few months to catch new exposures early. ## Frequently Asked Questions ### Is it safe to enter my password here? Yes! Your password never leaves your browser. We only send a partial hash (first 5 characters) to check against the database, making it impossible to reverse-engineer your actual password. ### What is k-Anonymity? k-Anonymity is a privacy technique where your search query is anonymized by requesting a range of results, hiding your specific query within a larger set of possibilities. ### What should I do if my password was breached? Change the password immediately on all accounts where you use it. Use a unique, strong password for each account, and consider using a password manager. ### How often is the breach database updated? The Have I Been Pwned database is continuously updated as new breaches are discovered and verified. It contains billions of compromised passwords. ### Does this tool store or log my password? No. On this page your password is hashed within your browser using SHA-1, and only the first 5 characters of the hash are sent to Have I Been Pwned. No plain-text password or full hash is stored, logged, or transmitted. The REST and MCP API is different: if you send a password there, it travels to FindUtils over TLS, is hashed on the server, and only the 5-character prefix goes on to Have I Been Pwned; it is not logged. To keep the password on your side with the API, send sha1_prefix instead and match the returned range yourself. ### Can I check multiple passwords at once? The tool checks one password at a time to keep the process simple and transparent. You can run as many individual checks as you need without any usage limits. ### What does the breach count number mean? The breach count tells you how many times that exact password has appeared across all known data breaches in the Have I Been Pwned database. A higher number means the password is widely compromised and should be changed immediately. ### Is a password safe just because it was not found in a breach? Not necessarily. A clean result means the password has not appeared in any publicly known breach so far. It could still be weak or guessable. Use the Password Strength Checker to evaluate its overall resilience. ### How is this different from checking my email on Have I Been Pwned? Checking your email tells you which services leaked your account data. Checking your password tells you whether that specific password string exists in any breach database. Both checks are complementary and serve different purposes. ### Does this work for passwords in languages other than English? Yes. The tool hashes whatever text you enter, regardless of the language or character set. Unicode passwords, special characters, and non-Latin alphabets are all supported. ## Related Tools - [Password Generator](https://findutils.com/security/password-generator/) - [Password Strength Checker](https://findutils.com/security/password-strength-checker/) - [Password Pattern Validator](https://findutils.com/security/password-pattern-validator/) - [2FA Code Tester](https://findutils.com/security/two-fa-code-tester/) - [Hash Comparison Tool](https://findutils.com/security/hash-comparison-tool/) - [Text Encryption](https://findutils.com/security/text-encryption/) - [Secure Note Sharing](https://findutils.com/security/secure-note-sharing/) - [Random Key Generator](https://findutils.com/security/random-key-generator/)