Password Strength Checker
Entropy, crack-time estimate and plain-English advice.
Everything is computed in your browser — the password never leaves this page. Estimates assume an attacker at 1011 guesses/second (modern hardware), which is why a long passphrase often beats a short “complex” password.
How to use the Password Strength Checker tool
- Enter your password strength in the fields above.
- Adjust any slider or type an exact number — the answer updates as you go.
- Copy the result and close the tab. Nothing you entered was sent anywhere.
About the Password Strength Checker tool
Estimates entropy in bits from character classes and uniqueness, flags common dictionary patterns, and translates the result into an offline crack-time estimate at roughly a hundred billion guesses per second.
The headline finding matches most security guidance: length beats symbol-spice. A 16-character passphrase usually beats an 8-character password with everything in it.
Everything runs locally in your browser: no data is uploaded, no account is needed, and it works offline once the page has loaded.
Embed this tool
Customize and copy an iframe. Linking back helps both sites.