Password Strength Checker
Type a password to see its entropy, realistic crack-time estimates, and weaknesses like common patterns. Your input never leaves this page — no network requests are made with it, ever.
About this tool
Entropy is estimated the standard way: the character-set size implied by the classes you actually use (lowercase 26, uppercase 26, digits 10, symbols 32) raised to the password's length, expressed in bits. Crack times assume an attacker must search half that space on average, at three realistic speeds — a rate-limited online attack, a single cracking GPU, and a large cluster. The pattern checks then flag things pure entropy math misses: dictionary passwords, keyboard walks, sequences, repeats, and years, which real cracking tools try first.
This check runs entirely in your browser with plain JavaScript. Your password is never sent anywhere — the page makes no network request containing your input, nothing is stored, and there is no server-side component at all. For real accounts, prefer a password manager with long random passwords and enable two-factor authentication.