README

b64web

Base64 and Base64URL (RFC 4648) encoding/decoding/validation for web browsers

Features

Encodes binary data or text string to Base64 or Base64URL data.
Decodes Base64 or Base64URL data to binary data or text string.
Autodetects alphabets and padding.
Validates Base64/Base64URL data, respects canonical encodings.
ES6 module, typings available

Install

npm i b64web

Usage

let b64s: string; // Base64/Base64URL encoded ASCII string
let data: ArrayBuffer; // binary data
let text: string; //text string data

Decoding Base64 data

// decode 'b64s' to binary data
data = decode(b64s);
// decode 'b64s' to binary data, convert the data to text string using text decoder 'decoder'
text = decode(b64s, decoder);

Encoding Base64 data

// encode binary data 'data' to Base64 ASCII string
b64s = encode(data);
// encode binary data 'data' to Base64URL ASCII string
b64s = encode(data, { urlsafe: true }); 
// encode text sting 'text' to binary data, convert to Base64 ASCII string
b64s = encode(text);

Validating Base64 data

// validate Base64/Base64URL encoded ASCII string
let valid = validate(b64s);

Examples

import * as B64 from 'b64web';

const s1 = 'foob';
const s2 = '\u{1F601} \u{1F4A3}!'; // '😁 💣!'
const buf = Uint32Array.from([0xFFFFFFF8]).buffer; // [248,255,255,255]

// Encode text string
const e1 = B64.encode(s1); // 'Zm9vYg=='
const e2 = B64.encode(s1, { nopadding: true }); // 'Zm9vYg'
const e3 = B64.encode(s2); // '8J+YgSDwn5KjIQ=='
const e4 = B64.encode(s2, { urlsafe: true, nopadding: true }); // '8J-YgSDwn5KjIQ'

// Decode to text string
const t1 = B64.decode(e1, 'utf-8'); // 'foob'
const t2 = B64.decode(e2, 'utf-8'); // 'foob'
const t3 = B64.decode(e3, 'utf-8'); // '😁 💣!'
const t4 = B64.decode(e4, 'utf-8'); // '😁 💣!'

// Decode to binary data
const b1 = B64.decode(e1); // [102,111,111,98]
const b2 = B64.decode(e2); // [102,111,111,98]
const b3 = B64.decode(e3); // [240,159,152,129,32,240,159,146,163,33]
const b4 = B64.decode(e4); // [240,159,152,129,32,240,159,146,163,33]

// Encode binary data
const x1 = B64.encode(b1); // 'Zm9vYg=='
const x2 = B64.encode(b3, { nopadding: true }); // '8J+YgSDwn5KjIQ'
const x3 = B64.encode(buf); // '+P///w=='
const x4 = B64.encode(buf, { urlsafe: true }); // '-P___w=='

// Validate
const v1 = B64.validate('Zm9vYg=='); // true
const v2 = B64.validate('Zm9vYg'); // true
const v3 = B64.validate('Zm9vYg', { nopadding: false }); // false, padding required
const v4 = B64.validate('Zm9vYh=='); // false, non-canonical
const v5 = B64.validate('8J-YgSDwn5KjIQ'); // true
const v6 = B64.validate('8J-YgSDwn5KjIQ', { urlsafe: false } ); // false, BASE64 required
const v7 = B64.validate('8J+YgSDwn5KjIQ', { urlsafe: true } ); // false, BASE64URL required

// TEXT <-> BINARY
const c1 = B64.stob(s1); // [102,111,111,98]
const d1 = B64.btos(c1); // 'foob'

Encoding a text string is equivalent to converting the text string to a binary buffer and encoding the buffer.

encode(text, { encoder }) === encode(stob(text, encoder))

Decoding Base64 data to text string is equivalent to decoding the data to binary buffer and converting the buffer.

decode(data, decoder) === btos(decode(data), decoder)

Usage no npm install needed!