Password Strength Checker

Evaluates password strength in real time using a heuristic scoring algorithm that combines length, character variety, common-pattern penalties, and entropy, then estimates brute-force crack time at 10 billion guesses per second. It also includes a built-in generator (length 4-64, uppercase/lowercase/numbers/symbols) and reports six criteria checks (>=8 chars, uppercase, lowercase, digit, symbol, >=12 chars) with pass/fail indicators.

1. Type or paste a password into the input (use the eye icon to toggle visibility, the X to clear, the copy icon to copy). 2. Or use the generator: set length (4-64) via the slider, tick the character sets, and click Generate. 3. The Strength Meter card updates live with a 0-100 score, color bar, and label (very weak / weak / fair / strong / very strong). 4. The three stat cards show estimated crack time, password length, and entropy in bits. 5. The Criteria card lists which checks passed (green check) or failed (gray X).

Score starts at 0 and adds min(30, length*2) for length, +10 per character variety (upper/lower/digit/symbol), +10 if length >= 12, +10 if length >= 16, with penalties for 3+ repeated characters (-10) and common prefixes like password/qwerty/abc/123/admin (-20). Entropy = length * log2(poolSize) where pool sizes are 26/26/10/32. Crack time assumes 1e10 guesses/second: combinations = poolSize^length / guessesPerSecond. Thresholds map to very weak (<20), weak (20-39), fair (40-59), strong (60-79), very strong (80+).