# Bun Read a file to an ArrayBuffer

> Read a file to an ArrayBuffer

- Skill: `jarle/bun-read-a-file-to-an-arraybuffer` (Agent Skill)
- Install (CLI): `npx skillmds@latest add jarle/bun-read-a-file-to-an-arraybuffer`
- Raw SKILL.md: https://api.skillmd.com/api/skills/jarle/bun-read-a-file-to-an-arraybuffer/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: jarle (https://skillmd.com/u/jarle)
- Updated: 2026-09-21
- Page: https://skillmd.com/skills/jarle/bun-read-a-file-to-an-arraybuffer

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# Read a file to an ArrayBuffer

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`.

```ts index.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}}
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()`](/guides/read-file/uint8array).

```ts index.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}}
const buffer = await file.arrayBuffer();
const bytes = new Int8Array(buffer);

bytes[0];
bytes.length;
```

***

Refer to the [Typed arrays](/runtime/binary-data#typedarray) docs for more information on working with typed arrays in Bun.