Password Entropy

Name: Password Entropy
Author: Daniel Cáceres López

Estimate password strength (local, nothing stored).

READY

password_entropy.tool

READY

Entropie

0 bit

Bewertung

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// HOW IT WORKS

Password entropy estimates how hard a password is to guess, in bits, from its length and the size of the character set. The tool computes it and rates the strength.

Formula

H = L · log2(R)
(L = length, R = size of the character pool)

Example

12 chars from lower+upper+digits (R = 62) → 12·log2(62) ≈ 71 bits.

Notes

Entropy assumes random characters; real words and patterns are far weaker than the formula suggests.
Roughly: < 50 bits weak, 50–70 fair, > 70 strong — but a unique passphrase beats a short complex one.