The score and the entropy disagree — which do I trust?

Entropy is closer to real strength, but it assumes uniform randomness: `correct horse battery staple` scores only 5/7 yet carries about 165 bits (long and irregular), while `aaaaAAAA1111!!!!` takes the full 7/7 with high entropy and is only caught by the repeat warning. Judge passphrases by entropy and "will the site accept it" by the score.

Does this tool store or upload my password?

No: the analysis runs in browser memory, with no localStorage write and no network request. Even so, do not paste a production password into any web page — including this one. Test a similar-but-different passphrase instead.

Password Strength

Judge how long a password would take to crack.

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Processed locally

About Password Strength

Estimates strength and crack time and points out what the password is missing — checked locally, never sent.

1
The score is **rule-based**: three length tiers (≥8 / ≥12 / ≥16, one point each) plus four character classes (lower, upper, digit, symbol, one point each) for a maximum of 7, mapped onto five labels from weak to very strong.
2
It also estimates **entropy**: `length × log2(pool)`, where the pool adds up the classes actually used (26 lower, 26 upper, 10 digits, 33 symbols).
3
Triple repeats (`aaa`) and missing character classes are called out separately, and the input is masked by default with a toggle to reveal it.

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