Password Strength Checker

The Password Strength Checker analyzes any password and scores it on a five-level scale using length, character classes and estimated entropy — with a realistic time-to-crack estimate and a checklist of what to improve.

Strength is math: password entropy = length × log₂(character pool), and every added bit doubles the attacker's work. An 8-character lowercase password holds ~38 bits and falls in seconds to offline cracking; 14 mixed characters push past 80 bits and into the centuries.

The checker also flags the failures math ignores — common passwords like 'password123' and repeated runs like 'aaa' that appear in breach lists regardless of length. Use it with the Password Generator to see what 'strong' actually looks like.