Free Online Password Strength Checker

1. Type a sample password into the Password field.
2. Watch the 0–100 score, label and entropy update live as you type.
3. Read the crack-time estimate and the list of specific suggestions.
4. Tweak length and character variety until the score reaches "strong" or "very strong".

Strength scoring blends two ideas: how many possible passwords there are of your shape (entropy, in bits) and how predictable yours is given known patterns. This tool starts from the entropy of an unrestricted draw across the character classes used, then applies penalties for repetition, common keyboard sequences (qwerty, 12345), and matches against a built-in list of the top 100 leaked passwords from breach corpuses like RockYou and Have I Been Pwned.

The crack-time estimate assumes an offline attacker capable of 10 billion guesses per second against a fast hash — roughly a single high-end consumer GPU. Anything above a few centuries is a practical brick wall; anything under "days" should be treated as already broken.

The golden rules: length beats complexity (a 20-character passphrase beats an 8-character symbol soup), uniqueness beats strength (a reused strong password is leaked the moment the weakest site is breached), and storage beats memory (use a password manager). Despite the local-only computation, do not paste a real production password into any web tool — type a representative sample instead.