Password Strength
Test a password for length, patterns and dictionary words.
About Password Strength
Password Strength estimates entropy and offline crack time, and flags the specific weaknesses that make a password worse than its length suggests — dictionary words, keyboard runs, repeated characters, embedded years. Checked entirely in your browser: there is no server, so nothing is transmitted.
How to use it
- Type or paste a password.
- Read the strength bar, entropy and estimated crack time.
- Check the weaknesses list — those are what make a password fail in practice.
Questions
Is it safe to type a real password here?
Safer than any hosted checker, since there is no server to receive it and no analytics script. If you are unsure, test a variation with the same structure instead.
What does entropy mean?
Bits of unpredictability. Each extra bit doubles the guesses needed. Under 50 is weak, 80 is solid, over 100 is beyond any realistic offline attack.
What does "offline crack time" assume?
An attacker who has stolen a password database and can try around 100 billion guesses a second on dedicated hardware. Online guessing against a live site is far slower, but database breaches are common.
My password scored well but is a real word with numbers. Is it fine?
No — the weaknesses list exists for exactly that. Entropy maths assumes randomness; a dictionary word is tried early regardless of how long it is.
Password Strength is free and runs entirely in your browser. No account, no upload, no watermark, no limit on use.