Security Tools
Password Entropy Calculator
Type a password to calculate its entropy in bits and an estimated brute-force crack time.
0.0 bits
Entropy
0
Character pool size
instantly
Est. time to brute-force
Assumes 10 billion guesses/second (a fast offline attack) and a purely random password — real-world crack time is often much faster for predictable or dictionary-based passwords. Your password never leaves your browser.
How to use this tool
- 1Type a password.
- 2See its entropy and estimated crack time.
- 3Your password never leaves your browser.
Frequently asked questions
What is password entropy?+
Entropy measures how unpredictable a password is, in bits — higher entropy means exponentially more possible combinations an attacker would need to try.