Is My Password Leaked?

Check if your password has been exposed in a data breach. We use the HaveIBeenPwned k-Anonymity API so your password never leaves your browser. Powered by a database of over 12 billion compromised passwords.

Enter Your Password

Type your password below. It will be hashed locally and checked against known data breaches. Nothing is sent to any server in plain text.

100% Client Side — Your password never leaves this device
Scanning breach databases...
Computing SHA-1 hash...
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This Password Has Been Leaked!
0
This password was found in 0 data breaches. Attackers use leaked password lists to break into accounts. Change it immediately on all accounts where you use it.
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Not Found in Any Known Breach
This password was not found in any known data breaches. That said, always use unique passwords for each account and enable two factor authentication (2FA) wherever possible.
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Unable to reach the HaveIBeenPwned API. Please try again in a moment.

How It Works: k-Anonymity

Your password is never sent anywhere. Here is the exact process that keeps you safe:

1
You Type
Enter your password in the field above. It stays in your browser.
2
SHA-1 Hash
Your browser computes a SHA-1 hash using the Web Crypto API. No server involved.
3
Send Prefix
Only the first 5 characters of the hash are sent to the API. The API cannot reverse this.
4
Match Locally
The API returns ~800 hash suffixes. Your browser checks for a match locally.

Frequently Asked Questions

Is it safe to type my password here?
Yes, your password never leaves your browser. We use a technique called k-Anonymity where only the first 5 characters of the SHA-1 hash of your password are sent to the HaveIBeenPwned API. The API cannot determine your actual password from those 5 characters. All processing happens locally in your browser using the Web Crypto API. You can verify this by opening your browser's developer tools and checking the Network tab.
What is HaveIBeenPwned?
HaveIBeenPwned is a free service created by security researcher Troy Hunt. It aggregates data from known data breaches and contains over 12 billion compromised passwords collected from hundreds of data breaches. The service provides a secure API that lets you check if a password has appeared in any known breach without revealing the password itself.
What should I do if my password was leaked?
Change the password immediately on all accounts where you use it. Use a password manager to generate a unique, strong password for each account. Enable two factor authentication (2FA) wherever possible. Never reuse passwords across multiple services. You can use our Password Generator to create a strong replacement.
How does k-Anonymity work?
k-Anonymity is a privacy technique. Your password is hashed using SHA-1, and only the first 5 characters of that hash (the prefix) are sent to the API. The API returns all hash suffixes that match that prefix, typically 500 to 800 results. Your browser then checks locally whether the full hash appears in those results. The API never sees enough information to determine your password.
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Generate a Strong Password
Create a random, secure password that has never appeared in any data breach.
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Why You Should Check If Your Password Has Been Leaked

Data breaches happen constantly. Major companies like LinkedIn, Adobe, Dropbox, and Yahoo have all suffered breaches that exposed millions of passwords. When your password appears in a breach, attackers add it to massive dictionaries used in credential stuffing attacks, where they try the same password across thousands of websites automatically. Checking whether your password has been compromised is the first step toward securing your accounts.

What is a Data Breach?

A data breach occurs when unauthorized individuals gain access to a company's database containing user credentials. These stolen credentials, often including email addresses and passwords, are then sold or shared on dark web forums. Even if you change your password on the breached site, attackers can try the same password on every other service you use. This is why password reuse is so dangerous.

Understanding the HaveIBeenPwned Database

The HaveIBeenPwned database, maintained by security researcher Troy Hunt, contains over 12 billion unique compromised passwords collected from hundreds of confirmed data breaches. When you use this tool, you are checking your password against this comprehensive database. The database is continuously updated as new breaches are discovered, making it one of the most reliable sources for checking password exposure.

Why k-Anonymity Matters

Traditional breach checking would require sending your actual password to a server, which creates a new security risk. The k-Anonymity model solves this by sending only the first 5 characters of your password's SHA-1 hash. With 2^20 (about 1 million) possible 5-character hex prefixes, each prefix returns hundreds of matching suffixes. This means the API operator cannot determine which specific password you were checking, even if they logged every request.

Best Practices for Password Security

Use a unique password for every account. Use a reputable password manager to generate and store complex passwords. Enable two factor authentication (2FA) on all important accounts, including email, banking, and social media. Regularly check your passwords against known breaches using this tool. Consider using passkeys or hardware security keys for your most critical accounts. Never share passwords via email, chat, or text messages. Use a tool like SecureBin for secure sharing.