パスワード強度チェッカー

よくある質問

›Is my password sent anywhere?

No — strength estimation runs entirely in your browser. Nothing is logged.

›What does entropy mean?

Bits of randomness — roughly, how many guesses an attacker would need. 50 bits is okay; 80+ is strong; 128+ is excellent.

›Why does 'P@ssw0rd!' get a low score?

Common substitutions (a→@, o→0) are the first thing password crackers try. The pattern 'capital + word + symbol + digit' adds very little real strength.

›Is a long passphrase better than a short complex one?

Usually yes. 'correct horse battery staple' is much stronger than 'P@ssw0rd!' — length wins over complexity.

›Is the checker free?

Yes — fully free, no signup.