Yet another Base64 transcoder in pure-JS
npm install js-base64
Yet another [Base64] transcoder.
[Base64]: http://en.wikipedia.org/wiki/Base64
``shell`
$ npm install --save js-base64
Locally…
`html`
… or Directly from CDN. In which case you don't even need to install.
`html`
This good old way loads Base64 in the global context (window). Though Base64.noConflict() is made available, you should consider using ES6 Module to avoid tainting window.
locally…
`javascript`
import { Base64 } from 'js-base64';
`javascript`
// or if you prefer no Base64 namespace
import { encode, decode } from 'js-base64';
or even remotely.
`html`
`html`
`javascript`
const {Base64} = require('js-base64');
Unlike the case above, the global context is no longer modified.
You can also use [esm] to import instead of require.
[esm]: https://github.com/standard-things/esm
`javascript`
require=require('esm')(module);
import {Base64} from 'js-base64';
`javascript`
let latin = 'dankogai';
let utf8 = '小飼弾'
let u8s = new Uint8Array([100,97,110,107,111,103,97,105]);
Base64.encode(latin); // ZGFua29nYWk=
Base64.encode(latin, true); // ZGFua29nYWk skips padding
Base64.encodeURI(latin); // ZGFua29nYWk
Base64.btoa(latin); // ZGFua29nYWk=
Base64.btoa(utf8); // raises exception
Base64.fromUint8Array(u8s); // ZGFua29nYWk=
Base64.fromUint8Array(u8s, true); // ZGFua29nYW which is URI safe
Base64.encode(utf8); // 5bCP6aO85by+
Base64.encode(utf8, true) // 5bCP6aO85by-
Base64.encodeURI(utf8); // 5bCP6aO85by-
`javascript`
Base64.decode( 'ZGFua29nYWk=');// dankogai
Base64.decode( 'ZGFua29nYWk'); // dankogai
Base64.atob( 'ZGFua29nYWk=');// dankogai
Base64.atob( '5bCP6aO85by+');// 'å°é£¼å¼¾' which is nonsense
Base64.toUint8Array('ZGFua29nYWk=');// u8s above
Base64.decode( '5bCP6aO85by+');// 小飼弾
// note .decodeURI() is unnecessary since it accepts both flavors
Base64.decode( '5bCP6aO85by-');// 小飼弾
`javascript`
Base64.isValid(0); // false: 0 is not string
Base64.isValid(''); // true: a valid Base64-encoded empty byte
Base64.isValid('ZA=='); // true: a valid Base64-encoded 'd'
Base64.isValid('Z A='); // true: whitespaces are okay
Base64.isValid('ZA'); // true: padding ='s can be omitted
Base64.isValid('++'); // true: can be non URL-safe
Base64.isValid('--'); // true: or URL-safe
Base64.isValid('+-'); // false: can't mix both
By default Base64 leaves built-in prototypes untouched. But you can extend them as below.
`javascript`
// 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- ab alias of .toBase64(true)
'小飼弾'.toBase64URL(); // 5bCP6aO85by- an alias of .toBase64URI()
'ZGFua29nYWk='.fromBase64(); // dankogai
'5bCP6aO85by+'.fromBase64(); // 小飼弾
'5bCP6aO85by-'.fromBase64(); // 小飼弾
'5bCP6aO85by-'.toUint8Array();// u8s above
`javascript`
// you have to explicitly extend Uint8Array.prototype
Base64.extendUint8Array();
// once extended, you can do the following
u8s.toBase64(); // 'ZGFua29nYWk='
u8s.toBase64URI(); // 'ZGFua29nYWk'
u8s.toBase64URL(); // 'ZGFua29nYWk' an alias of .toBase64URI()
`javascript`
// extend all at once
Base64.extendBuiltins()
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.
Or even better, Base64.toUint8Array(pngBase64).
* Since version 3.3 it is written in TypeScript. Now base64.mjs is compiled from base64.ts then base64.js is generated from base64.mjs.base64.js
* Since version 3.7 is ES5-compatible again (hence IE11-compatible).js-base64` switch to ES2015 module so it is no longer compatible with legacy browsers like IE (see above)
* Since 3.0