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Password Strength Checker
How long a password would take to crack, checked without sending it anywhere.
Free. Runs in your browser: nothing you enter or open is uploaded.
Waiting for a password
- Length
- Character types
- Online attack (rate limited)
- Offline attack, fast hash
The check runs on your device. The password is never sent anywhere, not even to NerdBible.
How to use it
- Type or paste the password into the box. Use Show to see what you typed.
- Read the verdict and the time an attacker would need, then the tips under it.
- Change anything flagged, or generate a new random password.
Questions
Is it safe to type my real password here?
The check runs entirely in your browser and nothing is sent or saved. Even so, the safest habit is to test a password of the same style rather than the real one.
How is the strength worked out?
From the length and the kinds of characters used, with penalties for common passwords, keyboard runs, repeats and sequences that attackers try first. The times assume a guessing rate of 10 billion a second offline and 100 an hour online.
What makes a password strong?
Length and randomness. A long random password or a passphrase of five or more random words beats a short one full of symbols.