Password Strength Checker

Free

Analyze password strength with entropy calculation, pattern detection and crack time estimates. Your password never leaves your browser.

Start typing above to analyze password strength

Analysis runs entirely in your browser

How Entropy Is Calculated

Entropy = length × log₂(character_pool_size). A password using only lowercase letters has a pool of 26; add numbers (+10), uppercase (+26) and symbols (+32). Higher entropy = more guesses needed to crack. 80+ bits is considered very strong against modern GPU-based attacks (~10 billion guesses/second).

Password Strength Checker

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