Mqtt.fx -

Beginners to intermediate MQTT users, hardware engineers testing IoT devices, and developers who need a clear, visual tool. Not ideal for: Automated load testing, CI/CD pipelines, or users needing a modern, dark-mode-first UI.

: It runs on Windows, macOS, and Linux.

→ You must use (paid). The classic 1.x version is MQTT 3.1.1 only. mqtt.fx

| Aspect | Rating | Notes | |--------|--------|-------| | Message throughput | ⭐⭐⭐ | Good for manual testing, but not designed for thousands of msgs/sec. | | Memory usage | ⭐⭐⭐ | ~150-250 MB idle – high for a simple MQTT client (Java overhead). | | Connection stability | ⭐⭐⭐⭐ | Very stable with standard brokers (Mosquitto, EMQX, HiveMQ). | | Reconnect logic | ⭐⭐⭐ | Auto-reconnect works, but not as sophisticated as CLI tools. | → You must use (paid)