Base64 ArrayBuffer is a lightweight utility library for encoding and decoding base64 data to and from ArrayBuffers in JavaScript and TypeScript environments. It provides high-performance conversion between binary ArrayBuffer data and base64 string representations with optimized lookup tables and proper padding handling.
npm install base64-arraybufferimport { encode, decode } from "base64-arraybuffer";For CommonJS:
const { encode, decode } = require("base64-arraybuffer");import { encode, decode } from "base64-arraybuffer";
// Create an ArrayBuffer with some data
const buffer = new ArrayBuffer(8);
const view = new Uint8Array(buffer);
view[0] = 72; // 'H'
view[1] = 101; // 'e'
view[2] = 108; // 'l'
view[3] = 108; // 'l'
view[4] = 111; // 'o'
// Encode ArrayBuffer to base64 string
const base64String = encode(buffer);
console.log(base64String); // "SGVsbG8AAA=="
// Decode base64 string back to ArrayBuffer
const decodedBuffer = decode(base64String);
const decodedView = new Uint8Array(decodedBuffer);
console.log(Array.from(decodedView)); // [72, 101, 108, 108, 111, 0, 0, 0]Encodes ArrayBuffer data to a base64 string representation with proper padding.
/**
* Encodes ArrayBuffer data to base64 string
* @param arraybuffer - The binary data to encode
* @returns Base64 encoded string representation
*/
function encode(arraybuffer: ArrayBuffer): string;The encode function converts binary data stored in an ArrayBuffer into a base64-encoded string. It handles all ArrayBuffer sizes correctly and applies proper base64 padding according to RFC 4648 specifications.
Usage Examples:
import { encode } from "base64-arraybuffer";
// Encode text data
const textBuffer = new TextEncoder().encode("Hello World");
const encoded = encode(textBuffer.buffer);
console.log(encoded); // "SGVsbG8gV29ybGQ="
// Encode binary data (all possible byte values)
const binaryBuffer = new ArrayBuffer(256);
const binaryView = new Uint8Array(binaryBuffer);
for (let i = 0; i < 256; i++) {
binaryView[i] = i;
}
const encodedBinary = encode(binaryBuffer);
// Results in properly encoded base64 string with appropriate paddingDecodes a base64 string back to ArrayBuffer binary data.
/**
* Decodes base64 string to ArrayBuffer
* @param base64 - The base64 string to decode
* @returns ArrayBuffer containing the decoded binary data
*/
function decode(base64: string): ArrayBuffer;The decode function converts a base64-encoded string back into binary data stored in an ArrayBuffer. It properly handles base64 padding and efficiently processes the entire string using optimized lookup tables.
Usage Examples:
import { decode } from "base64-arraybuffer";
// Decode a base64 string
const decoded = decode("SGVsbG8gV29ybGQ=");
const text = new TextDecoder().decode(decoded);
console.log(text); // "Hello World"
// Decode with different padding scenarios
const decoded1 = decode("TWFu"); // No padding
const decoded2 = decode("TWE="); // Single padding
const decoded3 = decode("SGVsbG8gd29ybGRzIQ=="); // Double padding
// All decode operations return proper ArrayBuffer instances
console.log(decoded1 instanceof ArrayBuffer); // trueThe library uses several optimizations for performance: