Welcome to rstmqtt

rstmqtt turns MQTT traffic into a live topic tree. See what your broker is up to, inspect messages and send your own. It runs on Linux, Windows and macOS, with MQTT 3.1.1 and 5.

What you can do

• Browse topics with live counters, change highlights and filtering.
• Inspect payloads as text, JSON, hex or Base64; browse history and compare changes.
• Publish messages with QoS, retain and MQTT 5 properties, or clear retained messages.
• Connect over TLS using system certificates or your own CA.

Install and connect

Grab your binary from the latest release: rstmqtt-linux-x86_64, rstmqtt-windows-x86_64.exe or rstmqtt-macos-aarch64. On Linux and macOS, make it executable with chmod +x before launching it.

For source builds and Linux installation, see the README.

Click the pencil in the top bar, enter your broker settings and choose Connect. Defaults: localhost:1883, MQTT 3.1.1, and subscriptions to # and $SYS/# at QoS 0. Topics appear as messages arrive. See Connecting for the settings.