Introduction

MQTT over WebSocket enables real-time and two-way communication between IoT devices and web applications. MQTT WebSocket client tools make it easy for developers to debug the implementation of MQTT and WebSocket protocols in their IoT projects.

MQTT over WebSocket

This blog post will explore the top 3 MQTT WebSocket client tools highly recommended in 2023.

Free Public MQTT Broker

Before diving into the MQTT WebSocket tools, we need an MQTT Broker supporting WebSocket to communicate and test. We choose the free public MQTT broker available on broker.emqx.io.

MQTT Broker Info

Server: broker.emqx.io

TCP Port: 1883

WebSocket Port: 8083

SSL/TLS Port: 8883

Secure WebSocket Port: 8084

For more information, please check out: Free Public MQTT Broker

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1. MQTT.js

MQTT.js is an MQTT client library written in JavaScript and designed to run in both node.js and browser environments. It fully supports MQTT protocol versions 3.1.1 and 5.0, as well as TCP, TLS, and WebSocket transports.

MQTT.js is a simple and lightweight library that allows developers to easily connect to MQTT brokers and publish/subscribe to MQTT topics via WebSockets.

Additionally, MQTT.js provides good documentation and community support, making it easy for developers to get started and resolve any issues they may encounter.

GitHub Project: https://github.com/mqttjs/MQTT.js/

Features

MQTT v3.1.1 and v5.0 support
TCP, TLS/SSL, and WebSocket support
Automatic topic alias
Auto reconnection
Messages buffer

Installation

npm install mqtt -g

Usage Example

Here is an example of connecting to the free public broker via MQTT over WebSocket, subscribing to an MQTT topic, and sending and receiving messages.

var mqtt = require('mqtt')
// Connect the 8083 port with `ws` protocol.
var client = mqtt.connect('ws://broker.emqx.io:8083/mqtt')

client.on('connect', function () {
  // Subscribe to a topic
  client.subscribe('test/topic', function (err) {
    if (!err) {
      // Publish a message to a topic
      client.publish('test/topic', 'Hello mqtt')
    }
  })
})

// Receive messages
client.on('message', function (topic, message) {
  // message is Buffer
  console.log(message.toString())
  client.end()
})

2. MQTTX Web

MQTTX Web is a user-friendly, browser-based tool for online debugging, developing, and testing MQTT applications. It connects to an MQTT broker via a WebSocket client and offers an intuitive interface.

Developed by the EMQX team, MQTTX Web is an open-source tool that supports MQTT 3.1.1 and MQTT 5.0 protocols and WebSocket transports. It is licensed under Apache Version 2.0.

Free Online MQTTX Web: https://mqttx.app/web-client/

Official Website: https://mqttx.app/web

GitHub Project: https://github.com/emqx/MQTTX/tree/main/web

MQTTX Web

Features

User-friendly interface for beginners and advanced users
Browser-based, no need to download and install
Chatbox UI for sending/receiving MQTT messages
MQTT v3.1.1 and MQTT v5.0 support
MQTT over WebSocket support
Using Docker for local deployment

Usage Example

Open MQTTX Web using your web browser.
Create an MQTT connection using WebSocket:
Subscribe to an MQTT topic and publish messages to the topic:

3. Paho JavaScript Client

The Paho JavaScript Client is an MQTT browser-based client library written in Javascript that uses WebSockets to connect to an MQTT Broker.

Paho MQTT is an open-source MQTT client that implements MQTT 3.1.1, developed by the Eclipse Foundation. However, the project has not been actively maintained since June 2019.

Official Website: https://www.eclipse.org/paho/index.php?page=clients/js/index.php

GitHub Project: https://github.com/eclipse/paho.mqtt.javascript

Features:

MQTT 3.1.1 and WebSocket support
SSL / TLS support
Message Persistence
Automatic Reconnect

Usage Example

Please check out the project README for examples of usage.

Wrap up

MQTT.js is the best client library written in Javascript for web applications requiring MQTT over WebSocket, while the Paho JavaScript client is not actively developed. And MQTTX Web is the best client toolbox for debugging and testing MQTT over WebSocket.

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Tag: MQTT Websocket

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