MQTT Board

An open-source MQTT client tool for easy MQTT pub/sub, testing, and demonstration. Full MQTT 5.0 support. More details and screenshots in a dedicated article.

To stay in sync with the latest changes, subscribe to MQTT Board changelog on our forum.

MQTT Board on GitHub.

Start playing with MQTT connections now. Run

Bright & friendly

Designed according to Material Design guidelines MQTT Board is crisp and intuitive. It's also perfect for mobile use which makes access from any device a productive experience.

Multiple MQTT brokers support

Create connections to various brokers from a single screen. MQTT Board will work with any MQTT broker supporting secure WebSockets (WSS).

Detailed connection logs

The colorful and verbose logs for every connect/disconnect, pub/sub etc. are a blessing for extensive testing and trials with MQTT connections.

Full MQTT 5.0 support

MQTT Board is developed by flespi — a creator of the first MQTT 5.0-compliant broker on the market. All these features naturally migrated to the MQTT Board letting you see the latest specification of MQTT protocol in action. Shared subscriptions, will delay interval, response topic, and much more.


Yes, you can fork MQTT Board on GitHub and use it as a basis for your project.

Secure connections only

Since MQTT Board is a web tool running in the browser, it will only allow connection over WSS (WebSockets over SSL). Secure connections are demanded by all modern browsers.

Playing with MQTT connections

  • Open MQTT Board from the flespi panel.

  • Publisher and subscriber settings + logs on the same screen.

  • Use the tree view to navigate the topics hierarchy with ease.

Check MQTT board live
Start playing with your MQTT connections now