Password Strength Checker
Test password strength, entropy and real-world crack times. Check how strong your password is. Instant entropy estimate, offline crack-time scenarios and specific improvement tips. Runs entirely in your browser — nothing is sent anywhere.
About the Password Strength Checker
"P@ssw0rd123!" looks strong and falls in seconds — because attackers guess patterns, not random letters. This checker estimates your password's entropy (the real measure of guessability), simulates offline cracking at modern GPU speeds from hobbyist to nation-state budgets, and flags the classic weaknesses: dictionary words, keyboard walks, repeats and date patterns. Everything is evaluated locally in JavaScript; the page transmits nothing.
How to use the Password Strength Checker
- Type or paste the password to test.
- Watch the strength meter as you type.
- Review the crack-time scenarios.
- Apply the improvement tips and re-test.
Key features
- Entropy estimate in bits
- Crack-time scenarios at four attacker budgets
- Detects dictionary words and common patterns
- 100% local — nothing is uploaded
Is it safe to type my real password here?
What makes a password strong?
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