Password Entropy Calculator
Bits of entropy in your password and time to crack.
Entropy assumes the password is random across the detected pool. Real passwords with words or patterns are easier to guess than the bit count suggests. Crack times use a 10 billion guesses per second offline figure (a strong GPU on a fast hash) and 1000 per second online.
About
Entropy = log2(charset size ^ length). Password 'hunter2' has about 41 bits, 'correct horse battery staple' has 44, a random 14-char alphanumeric has 83. This shows entropy and crack time at common attacker speeds.
How to use
- Type a password.
- See entropy bits and estimated crack times.
FAQ
What's a strong password?+
60+ bits is strong. 80+ is overkill for online accounts (where rate limiting matters more). For local encryption, aim for 100+ bits.
What attack speed does this assume?+
10 billion guesses/sec for offline (matches a fast GPU on bcrypt). 1000/sec for online (typical rate limiting).