wangzhanyong / js-base64

Base64 implementation for JavaScript

base64.js

Yet another Base64 transcoder

Install

$ npm install --save js-base64

If you are using it on ES6 transpilers, you may also need:

$ npm install --save babel-preset-env

Note js-base64 itself is stand-alone so its package.json has no dependencies.  However, it is also tested on ES6 environment so "babel-preset-env": "^1.7.0" is on devDependencies.

Usage

In Browser

<script src="base64.js"></script>

node.js

var Base64 = require('js-base64').Base64;

es6+

import { Base64 } from 'js-base64';

SYNOPSIS

Base64.encode('dankogai');  // ZGFua29nYWk=
Base64.encode('小飼弾');    // 5bCP6aO85by+
Base64.encodeURI('小飼弾'); // 5bCP6aO85by-

Base64.decode('ZGFua29nYWk=');  // dankogai
Base64.decode('5bCP6aO85by+');  // 小飼弾
// note .decodeURI() is unnecessary since it accepts both flavors
Base64.decode('5bCP6aO85by-');  // 小飼弾

String Extension for ES5

if (Base64.extendString) {
    // you have to explicitly extend String.prototype
    Base64.extendString();
    // once extended, you can do the following
    'dankogai'.toBase64();       // ZGFua29nYWk=
    '小飼弾'.toBase64();         // 5bCP6aO85by+
    '小飼弾'.toBase64(true);     // 5bCP6aO85by-
    '小飼弾'.toBase64URI();      // 5bCP6aO85by-
    'ZGFua29nYWk='.fromBase64(); // dankogai
    '5bCP6aO85by+'.fromBase64(); // 小飼弾
    '5bCP6aO85by-'.fromBase64(); // 小飼弾
}

TypeScript

TypeScript 2.0 type definition was added to the DefinitelyTyped repository.

$ npm install --save @types/js-base64

.decode() vs .atob (and .encode() vs btoa())

Suppose you have:

var pngBase64 = 
  "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=";

Which is a Base64-encoded 1x1 transparent PNG, DO NOT USE Base64.decode(pngBase64).  Use Base64.atob(pngBase64) instead.  Base64.decode() decodes to UTF-8 string while Base64.atob() decodes to bytes, which is compatible to browser built-in atob() (Which is absent in node.js).  The same rule applies to the opposite direction.

SEE ALSO

• http://en.wikipedia.org/wiki/Base64