Comparing MQTT clients
There are several good MQTT clients, and the right one depends on how you work. Here's a quick, friendly overview of the popular options and what each is great at — plus where MQTT Viewer fits in.
MQTT Viewer
A free, open-source (GPL-3.0) native desktop client for macOS, Windows, and Linux. It's focused on visualizing and debugging broker traffic: a live topic tree, an interactive message timeline, message comparison, and Sparkplug B / Base64 / Hex decoding, with up to 10 simultaneous connections and full MQTT v3.1.1 and v5 over TCP, TLS, mutual TLS, and WebSocket. Best if you want a fast, focused, broker-neutral tool with no account or cost.
MQTT Explorer
A much-loved tool that popularized the hierarchical topic tree, free and cross-platform, and a favourite in the Home Assistant community. Great if you want a simple, familiar way to browse a broker. If you like its approach, see how MQTT Viewer builds on it on the MQTT Explorer alternative page.
MQTTX
A powerful, actively developed toolkit from the team behind EMQX, spanning a desktop app, a web client, and a CLI, with full MQTT 5.0, benchmarking, and a broad set of payload codecs. Great if you want an all-in-one toolset. For a lighter, more focused desktop option, see the MQTTX alternative page.
MQTT.fx
A mature, professional desktop client (current 5.x by Softblade) with a Topic Explorer, Sparkplug tooling, and commercial support, offered under paid licenses. Great if you want a polished commercial product with vendor support. If you'd prefer a free, open-source option, see the MQTT.fx alternative page.
Which should you choose?
They're all good — it comes down to fit. Choose MQTTX for an all-in-one toolkit with a CLI and web client; MQTT.fx for a commercial product with support; MQTT Explorer for a simple, familiar tree view; and MQTT Viewer for a fast, free, open-source desktop client focused on visualizing and debugging traffic. For a fuller rundown, read the best MQTT clients overview.
Frequently asked questions
What is MQTT Viewer best for?
MQTT Viewer is best for developers who want a fast, free, open-source desktop client focused on visualizing and debugging broker traffic — a live topic tree, an interactive timeline, payload decoding, and up to 10 simultaneous connections, on macOS, Windows, and Linux.
Is MQTT Viewer free and open source?
Yes. MQTT Viewer is free and open-source under the GPL-3.0 license, with full MQTT v3.1.1 and v5 support and no account required.
Does MQTT Viewer work with any broker?
Yes. MQTT Viewer is broker-neutral and works with any MQTT broker, including Mosquitto, EMQX, and HiveMQ.
Ready to try it? Download MQTT Viewer for macOS, Windows, or Linux — it's free and installs in seconds.
MQTT Viewer is free, open-source, and runs on macOS, Windows & Linux.
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