A modern, open-source MQTT Explorer alternative

MQTT Explorer popularised the topic-tree view of a broker. MQTT Viewer keeps that tree and adds multiple connections, a message timeline, a broker status page and full MQTT v5.

What people love about MQTT Explorer

MQTT Explorer's topic tree made it easy to see an entire broker at a glance. It plots numeric topics, diffs each message against the last and clears retained topics. It is free, runs on macOS, Windows and Linux, and is popular in the Home Assistant community.

MQTT Viewer does all of that too. It connects to any broker and shows every topic in a live tree.

How MQTT Viewer is different

Up to 10 connections at once. Development, staging and production side by side.
Full MQTT v3.1.1 and v5 over TCP, TLS, mutual TLS and WebSocket.
A message timeline. Drag, zoom and step through a topic's history.
A broker status page. $SYS metrics as tiles, with health warnings and the loudest topics.
A topic graph. The namespace drawn live, sized by rate and coloured by recency.
Payload decoding. Sparkplug B, Base64 and Hex, plus image previews.
Publish history and collections. Resend from the last 500 sends, or save messages into folders.
Client logs for each connection.
A native app for macOS, Windows and Linux, free and open source.

Frequently asked questions

Is MQTT Viewer similar to MQTT Explorer?

Yes. MQTT Viewer keeps the topic tree that made MQTT Explorer popular and adds multiple connections, MQTT v5, a message timeline, a broker status page and Sparkplug B decoding.

Is MQTT Viewer free and open source?

MQTT Viewer is free and open source under the GPL-3.0 licence, with no account required.

Can MQTT Viewer connect to several brokers at once?

MQTT Viewer supports up to 10 broker connections at once, each in its own tab.

Is MQTT Viewer actively developed?

MQTT Viewer is actively developed, with full MQTT v3.1.1 and v5 support over TCP, TLS, mutual TLS and WebSocket.

See the best MQTT clients overview, or download MQTT Viewer.

MQTT Viewer is free and open source, and runs on macOS, Windows and Linux.

Download MQTT Viewer