Work out password generator strength instantly with clear inputs, formula shown and shareable results.
Entropy is length times the base-two logarithm of the character set size, and the average crack time is half the search space divided by the guess rate. Each extra character adds a fixed number of bits, which is why length beats complexity: adding four characters helps more than adding symbols to a short password.
Entropy
bits = length x log2(character set size)
Crack time
average seconds = 2^bits / 2 / guesses per second
bits = length x log2(character set size). Entropy is length times the base-two logarithm of the character set size, and the average crack time is half the search space divided by the guess rate.
Each extra character adds a fixed number of bits, which is why length beats complexity: adding four characters helps more than adding symbols to a short password.
Enter password length, character set size, attacker guesses per second. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.