The best MQTT clients in 2026

Every tool below is worth knowing. They overlap in the basics — connect, subscribe, publish — and each brings something of its own. We'll start with MQTT Viewer (this site's app) and then cover the other great options.

MQTT Viewer — fast, free, focused

MQTT Viewer is a free, open-source (GPL-3.0) native desktop client for macOS, Windows, and Linux, built around a live topic tree for seeing and debugging broker traffic. It adds an interactive message timeline, message comparison, Sparkplug B / Base64 / Hex decoding, free-text and pattern filtering, and a searchable publish history, with up to 10 simultaneous connections and full MQTT v3.1.1 and v5 over TCP, TLS, mutual TLS, and WebSocket.

Best for: developers who want a fast, focused, broker-neutral desktop tool with no account, no cost, and a familiar tree-based view. Download it here.

MQTT Explorer — the classic topic tree

MQTT Explorer popularized the hierarchical topic-tree view and remains a favourite, especially in the Home Assistant and hobbyist communities. It's free, cross-platform, and refreshingly simple to pick up.

Best for: anyone who wants a straightforward, familiar way to browse a broker. See how MQTT Viewer builds on the same idea on the MQTT Explorer alternative page.

MQTTX — the all-in-one toolkit

From the team behind the EMQX broker, MQTTX is a powerful, actively developed suite spanning a desktop app, a web client, and a CLI, with full MQTT 5.0, benchmarking, and a broad set of payload codecs.

Best for: people who want one toolset that covers GUI, scripting via CLI, and a browser client. For a lighter desktop option, see the MQTTX alternative page.

MQTT.fx — the polished commercial option

The current MQTT.fx 5.x (by Softblade) is a mature, professional desktop client with a Topic Explorer, Sparkplug tooling, and commercial support, offered under paid licenses.

Best for: teams who want a polished commercial product with vendor support. If you'd prefer a free, open-source option, see the MQTT.fx alternative page.

HiveMQ web client — nothing to install

HiveMQ offers a free, browser-based MQTT client over WebSocket. There's nothing to download, which makes it handy for a quick connection test from any machine.

Best for: a fast, no-install check when you just need to poke at a broker from the browser.

How to choose

Think about how you like to work. Want a fast, free desktop app focused on visualizing traffic? MQTT Viewer. Want an all-in-one toolkit with a CLI? MQTTX. Prefer a simple classic tree? MQTT Explorer. Need commercial support? MQTT.fx. Just want something in the browser? The HiveMQ web client. You can mix and match, too — many developers keep more than one around.

Frequently asked questions

Curious about MQTT Viewer? Compare the options or download it for macOS, Windows, or Linux — it's free.