Quickly prototype your subscriber client with MIMIC and a public MQTT broker

The public MQTT brokers at

http://moxd.io/2015/10/public-mqtt-brokers/

allow you quickly to test your MQTT clients.

By using simulated sensors with MIMIC MQTT Simulator, you can
rapidly prototype your MQTT subscriber application to scale your
IoT environment. For example, this screenshot shows 100 simulated
sensors publishing arbitrary payload messages at predefined rate,
and a mosquitto subscriber client displaying them.

At the bottom left, the "10000-ft view" of the MIMICView GUI
allows you to monitor and control thousands of simulated sensors.
In this case we see the icons of 100 active sensors.
The MIMIC Log Window with diagnostic messages at bottom right
displays the traced MQTT activity of one of the sensors.
The Mosquitto subscriber at top right displays the received
JSON-formatted messages on one of the topics. The tcpdump
capture in the middle top shows the packets exchanged between
simulated sensors and broker.