Is my password sent anywhere?

No — this tool has no network calls at all for the password field. Everything is computed locally in your browser.

What does 'entropy' mean here?

It's an estimate of how many attempts a brute-force attacker would need, based on password length and character variety. Higher is better.

Why is a long password still rated weak?

Length alone isn't enough if the password is a common word, a keyboard pattern, or has repeated/sequential characters — those are checked separately from raw length.

Password Strength Checker

Type or paste a password to see its strength, estimated entropy, and specific tips to make it stronger — nothing leaves your browser.

This runs entirely in your browser — the password is never sent anywhere.

如何使用Password Strength Checker

1
Type or paste a password into the field.
2
Review the strength bar, entropy estimate and specific feedback.
3
Adjust your password until it reaches a strong rating.