Password Strength Checker
Check how strong a password is with an estimated strength score, entropy in bits and crack-time guidance. 100% local — nothing is sent.
| Attack scenario | Guess rate | Est. crack time |
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Need a stronger password? Password generator.
About this checker
Strength is based on length and character variety. For real accounts, use a long, unique passphrase and a password manager.
FAQ
Is my password sent anywhere?
No. The check runs entirely in your browser — your password is never uploaded, stored or logged, and this page never saves it on your device either.
How is strength estimated?
It estimates how many guesses a cracking tool would need: dictionary words (including l33t variants), repeated blocks, sequences, keyboard runs and years are recognized as patterns attackers try first — so "Aa1!Aa1!Aa1!" scores far lower than a naive length-times-variety formula would suggest.
Why does my "complex" password score low?
Attackers do not brute-force character by character — they try common words, substitutions (p@ssw0rd), repeats and keyboard patterns first. A password built from those patterns falls quickly no matter how many symbol classes it mixes.
What actually makes a strong password?
Length and randomness. Four or more unrelated random words, or 16+ random characters from a password manager, beat short "complex" passwords. Use a unique password per site and turn on 2FA — and only change passwords when there is a reason (breach), not on a schedule.
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