---
title: "k6/ws | Grafana k6 documentation"
description: "k6 WebSocket API"
---

# k6/ws

> 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.

The [`k6/ws` module](/docs/k6/latest/javascript-api/k6-ws/) provides a [WebSocket](https://en.wikipedia.org/wiki/WebSocket) client implementing the [WebSocket protocol](http://www.rfc-editor.org/rfc/rfc6455.txt).

Expand table

| Function                                                                          | Description                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [connect( url, params, callback )](/docs/k6/latest/javascript-api/k6-ws/connect/) | Create a WebSocket connection, and provides a [Socket](/docs/k6/latest/javascript-api/k6-ws/socket/) client to interact with the service. The method blocks the test finalization until the connection is closed. |

Expand table

| Class/Method                                                                                              | Description                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [Params](/docs/k6/latest/javascript-api/k6-ws/params/)                                                    | Used for setting various WebSocket connection parameters such as headers, cookie jar, compression, etc.                                                                                             |
| [Socket](/docs/k6/latest/javascript-api/k6-ws/socket/)                                                    | WebSocket client used to interact with a WS connection.                                                                                                                                             |
| [Socket.close()](/docs/k6/latest/javascript-api/k6-ws/socket/socket-close/)                               | Close the WebSocket connection.                                                                                                                                                                     |
| [Socket.on(event, callback)](/docs/k6/latest/javascript-api/k6-ws/socket/socket-on/)                      | Set up an event listener on the connection for any of the following events:  <br />\- open  <br />\- binaryMessage  <br />\- message  <br />\- ping  <br />\- pong  <br />\- close  <br />\- error. |
| [Socket.ping()](/docs/k6/latest/javascript-api/k6-ws/socket/socket-ping/)                                 | Send a ping.                                                                                                                                                                                        |
| [Socket.send(data)](/docs/k6/latest/javascript-api/k6-ws/socket/socket-send/)                             | Send string data.                                                                                                                                                                                   |
| [Socket.sendBinary(data)](/docs/k6/latest/javascript-api/k6-ws/socket/socket-sendbinary/)                 | Send binary data.                                                                                                                                                                                   |
| [Socket.setInterval(callback, interval)](/docs/k6/latest/javascript-api/k6-ws/socket/socket-setinterval/) | Call a function repeatedly at certain intervals, while the connection is open.                                                                                                                      |
| [Socket.setTimeout(callback, period)](/docs/k6/latest/javascript-api/k6-ws/socket/socket-settimeout/)     | Call a function with a delay, if the connection is open.                                                                                                                                            |