MQTT FX offers both free and paid versions. The free version has limitations, while the paid version offers advanced features, such as support for multiple connections, advanced filtering, and more. To access these advanced features, you need a valid license key.
MQTT.fx is a popular MQTT client tool used for testing and debugging MQTT connections. If you're looking for a free license key for MQTT.fx, here's what you need to know: mqtt fx license key free