---
title: "Socket.sendBinary(data) | Grafana k6 documentation"
description: "Send binary data through the connection."
---

# Socket.sendBinary(data)

> Note
> 
> A module with a better and standard API exists.
> 
> The new [k6/websockets API](/docs/k6/latest/javascript-api/k6-websockets/) partially implements the [WebSockets API living standard](https://websockets.spec.whatwg.org/).
> 
> When possible, we recommend using the new API. It uses a global event loop for consistency with other k6 APIs and better performance.

Send binary data through the connection.

Expand table

| Parameter | Type        | Description       |
|-----------|-------------|-------------------|
| data      | ArrayBuffer | The data to send. |

### Example

JavaScript ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```javascript
import ws from 'k6/ws';

const binFile = open('./file.pdf', 'b');

export default function () {
  ws.connect('http://wshost/', function (socket) {
    socket.on('open', function () {
      socket.sendBinary(binFile);
    });

    socket.on('binaryMessage', function (msg) {
      // msg is an ArrayBuffer, so we can wrap it in a typed array directly.
      new Uint8Array(msg);
    });
  });
}
```

- See also [Socket.send(data)](/docs/k6/latest/javascript-api/k6-ws/socket/socket-send/)