# Example with connection state recovery

This example shows how to use the [Connection state recovery feature](https://socket.io/docs/v4/connection-state-recovery).

![Video of the example](assets/csr.gif)

## How to use

```shell
# choose your module syntax (either ES modules or CommonJS)
$ cd esm/

# install the dependencies
$ npm i

# start the server
$ node index.js
```

And point your browser to `http://localhost:3000`.

You can also run this example directly in your browser on:

- [CodeSandbox](https://codesandbox.io/p/sandbox/github/socketio/socket.io/tree/main/examples/connection-state-recovery-example/esm?file=index.js)
- [StackBlitz](https://stackblitz.com/github/socketio/socket.io/tree/main/examples/connection-state-recovery-example/esm?file=index.js)