Password Strength Checker
Test any password instantly. See its entropy score, estimated crack time, and what to do to make it stronger. Your password is never sent to any server.
Type a password above to see your strength analysis.
Analysis happens entirely in your browser. Your password is never sent to any server.
How is password strength measured?
Password strength is measured by entropy — a mathematical measure of unpredictability expressed in bits. A password with 60 bits of entropy means there are 260 possible passwords of that type, requiring an attacker to test on average half of those (259) to guess it.
Entropy depends on two factors: the length of the password, and the character set size (26 for lowercase only, 52 for mixed case, 62 with digits, 94 with all standard symbols). Adding a character multiplies the search space by the entire charset size — which is why length is exponentially more powerful than adding a single symbol type.
The crack time estimate here assumes a GPU-accelerated offline attack at 10 billion guesses per second — the typical speed against weak hashing algorithms. Against properly implemented bcrypt or Argon2 with high cost factors, real-world crack times would be orders of magnitude longer.