What is MQTT?
MQTT (Message Queuing Telemetry Transport) is a lightweight publish-subscribe messaging protocol designed for low-bandwidth, high-latency networks — perfect for IoT.
Core Concepts
- Broker — The central server (e.g. Mosquitto, HiveMQ, AWS IoT Core)
- Publisher — Device that sends data to a topic
- Subscriber — Device that listens on a topic
- Topic — A string like
home/livingroom/temperature
Why MQTT for IoT?
Low overhead, reliable delivery with QoS levels, and secure communication over TLS make MQTT ideal for battery-powered and constrained devices.
Quick Example
An ESP32 publishes temperature to home/kitchen/temp. Your mobile app subscribes to the same topic and displays live readings instantly.
Getting Started
Try free brokers like HiveMQ Public Broker or host your own using Mosquitto on a Raspberry Pi.