Buffer

Warning

To use Node.js APIs in your Worker, add the nodejs_compat_v2 compatibility flag to your wrangler.toml file.

The Buffer API in Node.js is one of the most commonly used Node.js APIs for manipulating binary data. Every Buffer instance extends from the standard Uint8Array ↗ class, but adds a range of unique capabilities such as built-in base64 and hex encoding/decoding, byte-order manipulation, and encoding-aware substring searching.

import { Buffer } from 'node:buffer';

const buf = Buffer.from('hello world', 'utf8');

console.log(buf.toString('hex'));
// Prints: 68656c6c6f20776f726c64
console.log(buf.toString('base64'));
// Prints: aGVsbG8gd29ybGQ=

A Buffer extends from Uint8Array. Therefore, it can be used in any Workers API that currently accepts Uint8Array, such as creating a new Response:

const response = new Response(Buffer.from("hello world"));

You can also use the Buffer API when interacting with streams:

const writable = getWritableStreamSomehow();
const writer = writable.getWriter();
writer.write(Buffer.from("hello world"));

Refer to the Node.js documentation for Buffer ↗ for more information.