About this tool
Estimate how strong a password is from its length and character classes, all computed locally in your browser.
Frequently asked questions
How is entropy estimated?
It multiplies the password length by the bits per character implied by which character classes (lowercase, uppercase, digits, symbols) appear, with a penalty for very short passwords.
How accurate is the crack time?
It is a rough estimate assuming ten billion guesses per second and averages over the keyspace; real attacks vary widely, so treat it as a guideline.