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Free tool
Password strength checker
Check how strong your password is and whether it appeared in a data breach without sending it: only the first 5 characters of its SHA-1 hash are queried (k-anonymity).
Was it in a data breach?
Uses the public Have I Been Pwned (Pwned Passwords) API with k-anonymity: your browser computes the SHA-1 hash and only sends its first 5 characters; the match is done on your device. Your password never leaves your browser.
How strong is your password?
This password strength checker estimates how strong your password is from its length, character types and the most common weak patterns (popular passwords, sequences, repeats, years), and shows roughly how long a brute-force attack would take. You can also check whether the password appeared in a data breach using the Have I Been Pwned database with k-anonymity: your password is never sent, not even its full hash.
Frequently asked questions
Is my password sent to a server?
No. The analysis runs in your browser. For the breach check, your browser computes the SHA-1 hash and sends only its first 5 characters to Have I Been Pwned, which returns hundreds of similar hashes; the final match happens on your device.
What should I do if my password was found in a breach?
Change it everywhere you use it, use a different password for every account and turn on two-factor authentication. You can create a new one with our password generator.
Are the attack times exact?
They are estimates: they depend on the attacker's hardware and how the site stores passwords. Use them to compare passwords with each other.
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