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Kamil Baczkowicz edited this page Nov 15, 2017 · 2 revisions

mqtt-spy is an open source utility intended to help you with monitoring activity on MQTT topics. It's been designed to deal with high volumes of messages, as well as occasional publications.

mqtt-spy is a JavaFX application, so should work on any operating system with an appropriate version of Java 8 installed. It's been tried on various Linux distributions (Mint, Ubuntu, RedHat), Windows 7/8/10 and MacOS.

mqtt-spy-daemon is a Java-based command line tool that does not require a GUI environment. Basic functionality works with Java 7, whereas some of the advanced features like scripting require Java 8 to be installed.

Both tools are still in development, so over the next couple of months more features should become available. For details on what's currently available see the wiki.

Getting in touch

If you have any suggestions, find any bugs, or would like to contribute to the project, please get in touch, either via this page or Twitter (@mqtt_spy).


Control panel (mqtt-spy)

Connection tab (mqtt-spy)

Console output (mqtt-spy-daemon)


The following table shows a comparison of the key features between mqtt-spy-daemon and mqtt-spy (as seen on screenshots above).

Feature mqtt-spy-daemon mqtt-spy
User interface Console GUI
Required version of Java Java 7 or later Java 8 Update 60 or later
Supported MQTT protocol version 3.1 & 3.1.1 3.1 & 3.1.1
MQTT TLS/SSL support Yes Yes
Multiple connections
& connection management
- Yes
High availability (multiple server URIs, reconnection
& resubscription)
Yes Yes
Configuration file driven Yes Yes
Diagnostic logging Yes Yes
Manual publications - Yes
Scripted publications Yes (started automatically) Yes (started via GUI)
Automated testing (test cases) Yes Yes
Predefined subscriptions Yes Yes
Subscription scripts (e.g. auto-reply or payload reformatting) Yes Yes
Subscription management - Yes
Received message preview Yes (basic - in the log) Yes (advanced - GUI & log)
Message browsing & searching - Yes
Message content
decoding & formatting
Yes Yes
Topic summary,
topic filtering & searching
- Yes
Creating message audit log Yes Yes
Message audit log browsing - Yes
Message audit log replay Yes Yes
Charts / graphing - Yes
Processing statistics - Yes
Checking for updates at start-up - Yes