---
title: WebSockets
description: Miniflare will always upgrade Web Socket connections. The Worker must respond
with a status 101 Switching Protocols response including a webSocket. For
example, the Worker below implements an echo WebSocket server:
image: https://developers.cloudflare.com/dev-products-preview.png
---

> Documentation Index  
> Fetch the complete documentation index at: https://developers.cloudflare.com/workers/llms.txt  
> Use this file to discover all available pages before exploring further. 

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# WebSockets

* [WebSockets Reference](https://developers.cloudflare.com/workers/runtime-apis/websockets)
* [Using WebSockets](https://developers.cloudflare.com/workers/examples/websockets/)

## Server

Miniflare will always upgrade Web Socket connections. The Worker must respond with a status `101 Switching Protocols` response including a `webSocket`. For example, the Worker below implements an echo WebSocket server:

JavaScript

```
export default {  fetch(request) {    const [client, server] = Object.values(new WebSocketPair());
    server.accept();    server.addEventListener("message", (event) => {      server.send(event.data);    });
    return new Response(null, {      status: 101,      webSocket: client,    });  },};
```

When using `dispatchFetch`, you are responsible for handling WebSockets by using the `webSocket` property on `Response`. As an example, if the above worker script was stored in `echo.mjs`:

JavaScript

```
import { Miniflare } from "miniflare";
const mf = new Miniflare({  modules: true,  scriptPath: "echo.mjs",});
const res = await mf.dispatchFetch("https://example.com", {  headers: {    Upgrade: "websocket",  },});const webSocket = res.webSocket;webSocket.accept();webSocket.addEventListener("message", (event) => {  console.log(event.data);});
webSocket.send("Hello!"); // Above listener logs "Hello!"
```

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```