Read a file to an ArrayBuffer

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

index.ts

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

const buffer = await file.arrayBuffer();

Read the binary content of the ArrayBuffer with a typed array, such as Int8Array. For Uint8Array, use .bytes().

index.ts

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

bytes[0];
bytes.length;

See Typed arrays for more on working with typed arrays in Bun.