MQTT Explorer
An all-round MQTT client that provides a structured topic overview
...Users can inspect message payloads, publish messages, and monitor changes in real time. The application displays received values and helps identify communication problems between devices and services. Its visualization tools support analyzing numeric values and observing message activity. MQTT Explorer provides configurable broker connections and secure communication options. Available as a desktop application and through browser-based deployment, it is useful for home automation, industrial IoT development, and MQTT troubleshooting.