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Redmoon Converters
🌿 Health & Lifestyle

Password Strength & Entropy Calculator

Estimate your password entropy in bits and brute-force resistance against modern attacker speeds. Character pool, length and randomness analysis.

Pure client-side — your password never leaves the browser.
Entropy
Length · Pool chars · Rating
AttackerGuesses / secTime to crack (avg)
Character classPresentAdds to pool
How the math works

Entropy = length × log₂(pool size). Pool grows as you mix lowercase (+26), uppercase (+26), digits (+10), symbols (+33) and unicode (+~100 for first non-ASCII set). Cracking time is half the search space ÷ attacker rate.

This is a raw estimate. A real attacker uses dictionaries and rules — common phrases like "password123" fall in seconds despite "fair" entropy. Use a passphrase of 4+ random words or a manager-generated 16+ char password.

Also known as

password entropy calculatorpassword strength calculatorpassword bits of entropy

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