Password Strength Checker
Password Strength Checker is a free security tool that runs directly in your browser with no account required.
About this tool
Estimate how strong a password is with a visual strength meter, a 0-100 score, an entropy estimate, and specific warnings such as short length, low character variety, repeats, keyboard sequences, or common password words.
How to use
- Type or paste a candidate into the Password field.
- Read the strength meter and the Score, Entropy, and Character sets metrics.
- Fix any listed warnings and re-check until the label reaches Strong or better.
Frequently asked questions
How is the score calculated?
Entropy is estimated from the password's length and which character classes it uses (lowercase, uppercase, digits, symbols), then reduced for each detected weakness. Scores under 40 are Weak, 70+ Strong, and 90+ Very strong.
What patterns trigger warnings?
Length under 12 characters, fewer than three character classes, three or more repeated characters in a row, keyboard or number sequences like qwerty or 1234, and common words such as password or letmein.
Does it check breach databases?
No. This is an offline structural analysis; it cannot tell whether the exact password appeared in a data breach. Services like Have I Been Pwned cover that separately.
Is it safe to type a real password here?
The check runs entirely in your browser and the password is never transmitted or stored. That said, the safest habit is testing candidate passwords rather than ones already protecting accounts.
The meter says Strong; is my password definitely safe?
Strength estimation is a heuristic. A dictionary phrase with substitutions can score higher than it deserves, so prefer randomly generated passwords from the Password Generator when possible.