GuidesReading files

Read a file to an ArrayBuffer with Bun

The Bun.file() function accepts a path and returns a BunFile instance. The BunFile class extends Blob and allows you to lazily read the file in a variety of formats. Use .arrayBuffer() to read the file as an ArrayBuffer.

const path = "/path/to/package.json";
const file = Bun.file(path);

const buffer = await file.arrayBuffer();

The binary content in the ArrayBuffer can then be read as a typed array, such as Int8Array. For Uint8Array, use .bytes().

const buffer = await file.arrayBuffer();
const bytes = new Int8Array(buffer);


Refer to the Typed arrays docs for more information on working with typed arrays in Bun.