There are many different testing tools available for MQTT.
In the main these tools let you publish and subscribe to MQTT topics.
The ones I use on a regular basis are the mosquitto_pub and mosquitto_sub tools that come with mosquitto broker and the graphical tool MQTT explorer.
mosquittopub and mosquittosub Tools
These tools are part of the mosquitto install.
They are command line tools that let you publish messages and subscribe to messages.
They support all MQTT options except websockets.
They are quick and relatively easy to use and I use them on a daily basis.
See Using the mosquitto pub and sub tools
MQTT Explorer
This is a graphical tool and needs to be installed. I tend to use this when I need to publish JSON data as it is much easier than using the command line.
It is also excellent for getting an overview of MQTT topics on the broker and for deleting retained messages.
My Own Tools
Over the years I have developed a number of tools to solve specific problems that I have had.
One of the most popular has been the mosquitto config file analyser.
This is a python script that scans a mosquitto.conf file and extracts the configuration data from the file.
Simple Simulators
Often when working with clients I create a simple simulator to simulate aparticular relay or module they are using.
This is usually so that I can test things without having to access the device itself or the client network.
To do it I usually monitor the device on the network using my data logger.
This also gives me data to test with.
Test Tools, Simulators, Consulting Services and Help
If you need custom test tools or simulators developed in Python or node-red than I may be able to help.
Often when working on a project you may need to bounce a few ideas off someone.
So if need help and advice then I do offer general consulting services just use the Ask Steve page to get in touch.