---
title: "Client.connect( url, [options] ) | Grafana k6 documentation"
description: "Connect to an MQTT broker"
---

# Client.connect()

Establishes a connection to an MQTT broker. When the connection is successfully established, the `connect` event is triggered.

## Signature

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

```javascript
client.connect(url, options)
```

## Parameters

Expand table

| Parameter                | Type      | Description                                            |
|--------------------------|-----------|--------------------------------------------------------|
| url                      | string    | Broker URL (for example, `mqtt://broker.emqx.io:1883`) |
| options                  | object    | Optional connection configuration                      |
| options.keepalive        | number    | Keep-alive interval in seconds (default: 60)           |
| options.connect\_timeout | number    | Connection timeout in milliseconds (default: 30000)    |
| options.clean\_session   | boolean   | Whether to start with a clean session (default: true)  |
| options.servers          | string\[] | Array of broker URLs for failover                      |
| options.tags             | object    | Custom tags for metrics (key-value pairs)              |

## Supported broker URL schemas

Expand table

| Schema     | Description                          |
|------------|--------------------------------------|
| `mqtt://`  | Plain TCP connection (no encryption) |
| `mqtts://` | Secure connection over SSL/TLS       |
| `tcp://`   | Alias for `mqtt://`                  |
| `ssl://`   | Alias for `mqtts://`                 |
| `tls://`   | Alias for `mqtts://`                 |
| `ws://`    | MQTT over WebSocket                  |
| `wss://`   | MQTT over secure WebSocket           |

If the schema is omitted, `mqtt://` is used as the default.

## SSL/TLS configuration

The extension uses standard [k6 TLS configuration](/docs/k6/latest/using-k6/protocols/ssl-tls/) for all SSL/TLS settings. Configure certificates, verification, and other TLS-related options using k6’s environment variables and configuration files.