string-entropy

Calculate the information entropy of a string

As pointed out by other sources, string entropy is propably the most reliable way of scoring a password. This module implements the algorithm described here, using a variable sized alphabet based on the actual contents of the string.

Demo

A simple password strength meter that updates as you type.

Documentation

See the annotated sources src/index.ts.

Example

const { entropy } = require('string-entropy');

console.log(entropy('correct horse battery staple'));
// outputs  132
console.log(entropy('Secret01'));
// outputs    66