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Password Strength Checker

Instantly analyze how strong your password is — entropy, crack time, and detailed criteria. 100% local, nothing is ever transmitted.

Enter a password above
Start typing to see your password analysis.

How it works

1
Type your password
Enter it in the field above. It never leaves your browser — all analysis is purely local JavaScript.
2
Criteria check
The tool instantly checks length milestones, character variety (uppercase, lowercase, digits, symbols) and calculates the entropy in bits.
3
Crack time estimate
Based on entropy and an assumed offline attack rate of 10 billion guesses/second, we calculate a rough worst-case crack time.
4
Improve it
Use the checklist to see which criteria you're missing. Aim for at least 80 bits of entropy (Strong or Very Strong rating).