> ## Documentation Index
> Fetch the complete documentation index at: https://bun-1dd33a4e-farm-c9035eb1-hot-recreated-import-unwatched.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Web APIs

> Web-standard APIs supported by Bun for server-side JavaScript

Some Web APIs aren't relevant in the context of a server-first runtime like Bun, such as the [DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API#html_dom_api_interfaces) or [History API](https://developer.mozilla.org/en-US/docs/Web/API/History_API). Many others, though, are broadly useful outside of the browser context; when possible, Bun implements these Web-standard APIs instead of introducing new APIs.

The following Web APIs are partially or completely supported.

| Category | APIs |
| - | - |
| HTTP | [`fetch`](https://developer.mozilla.org/en-US/docs/Web/API/fetch), [`Response`](https://developer.mozilla.org/en-US/docs/Web/API/Response), [`Request`](https://developer.mozilla.org/en-US/docs/Web/API/Request), [`Headers`](https://developer.mozilla.org/en-US/docs/Web/API/Headers), [`AbortController`](https://developer.mozilla.org/en-US/docs/Web/API/AbortController), [`AbortSignal`](https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal) |
| URLs | [`URL`](https://developer.mozilla.org/en-US/docs/Web/API/URL), [`URLSearchParams`](https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams) |
| Web Workers | [`Worker`](https://developer.mozilla.org/en-US/docs/Web/API/Worker), [`self.postMessage`](https://developer.mozilla.org/en-US/docs/Web/API/DedicatedWorkerGlobalScope/postMessage), [`structuredClone`](https://developer.mozilla.org/en-US/docs/Web/API/structuredClone), [`MessagePort`](https://developer.mozilla.org/en-US/docs/Web/API/MessagePort), [`MessageChannel`](https://developer.mozilla.org/en-US/docs/Web/API/MessageChannel), [`BroadcastChannel`](https://developer.mozilla.org/en-US/docs/Web/API/BroadcastChannel) |
| Streams | [`ReadableStream`](https://developer.mozilla.org/en-US/docs/Web/API/ReadableStream), [`WritableStream`](https://developer.mozilla.org/en-US/docs/Web/API/WritableStream), [`TransformStream`](https://developer.mozilla.org/en-US/docs/Web/API/TransformStream), [`ByteLengthQueuingStrategy`](https://developer.mozilla.org/en-US/docs/Web/API/ByteLengthQueuingStrategy), [`CountQueuingStrategy`](https://developer.mozilla.org/en-US/docs/Web/API/CountQueuingStrategy) and associated classes |
| Blob | [`Blob`](https://developer.mozilla.org/en-US/docs/Web/API/Blob) |
| WebSockets | [`WebSocket`](https://developer.mozilla.org/en-US/docs/Web/API/WebSocket) |
| Encoding and decoding | [`Uint8Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array), [`Uint8Array.prototype.toBase64()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array/toBase64), [`Uint8Array.fromBase64()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array/fromBase64), [`TextEncoder`](https://developer.mozilla.org/en-US/docs/Web/API/TextEncoder), [`TextDecoder`](https://developer.mozilla.org/en-US/docs/Web/API/TextDecoder), [`atob`](https://developer.mozilla.org/en-US/docs/Web/API/atob), [`btoa`](https://developer.mozilla.org/en-US/docs/Web/API/btoa) |
| JSON | [`JSON`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON) |
| Timeouts | [`setTimeout`](https://developer.mozilla.org/en-US/docs/Web/API/setTimeout), [`clearTimeout`](https://developer.mozilla.org/en-US/docs/Web/API/clearTimeout) |
| Intervals | [`setInterval`](https://developer.mozilla.org/en-US/docs/Web/API/setInterval), [`clearInterval`](https://developer.mozilla.org/en-US/docs/Web/API/clearInterval) |
| Crypto | [`crypto`](https://developer.mozilla.org/en-US/docs/Web/API/Crypto), [`SubtleCrypto`](https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto), [`CryptoKey`](https://developer.mozilla.org/en-US/docs/Web/API/CryptoKey) |
| Debugging | [`console`](https://developer.mozilla.org/en-US/docs/Web/API/console), [`performance`](https://developer.mozilla.org/en-US/docs/Web/API/Performance) |
| Microtasks | [`queueMicrotask`](https://developer.mozilla.org/en-US/docs/Web/API/queueMicrotask) |
| Errors | [`reportError`](https://developer.mozilla.org/en-US/docs/Web/API/reportError) |
| User interaction | [`alert`](https://developer.mozilla.org/en-US/docs/Web/API/Window/alert), [`confirm`](https://developer.mozilla.org/en-US/docs/Web/API/Window/confirm), [`prompt`](https://developer.mozilla.org/en-US/docs/Web/API/Window/prompt) (intended for interactive CLIs) |
| Realms | [`ShadowRealm`](https://github.com/tc39/proposal-shadowrealm) |
| Events | [`EventTarget`](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget), [`Event`](https://developer.mozilla.org/en-US/docs/Web/API/Event), [`ErrorEvent`](https://developer.mozilla.org/en-US/docs/Web/API/ErrorEvent), [`CloseEvent`](https://developer.mozilla.org/en-US/docs/Web/API/CloseEvent), [`MessageEvent`](https://developer.mozilla.org/en-US/docs/Web/API/MessageEvent) |