bun-types/docs/guides/util/base64.md

Type definitions and documentation for Bun, an incredibly fast JavaScript runtime

---
name: Encode and decode base64 strings
---

Bun implements the Web-standard [`atob`](https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/atob) and [`btoa`](https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/btoa) functions for encoding and decoding base64 strings.

```ts
const data = "hello world";
const encoded = btoa(data); // => "aGVsbG8gd29ybGQ="
const decoded = atob(encoded); // => "hello world"
```

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See [Docs > Web APIs](https://bun.sh/docs/runtime/web-apis) for a complete breakdown of the Web APIs implemented in Bun.