A modern, open-source MQTT Explorer alternative

MQTT Explorer is a much-loved tool that popularized the topic-tree view of a broker. MQTT Viewer builds on that same idea in a fast, free, actively developed app — with the familiar tree plus multiple connections, an interactive timeline, and full MQTT v5.

What people love about MQTT Explorer

MQTT Explorer earned its place in a lot of toolboxes for good reasons. Its hierarchical topic tree made it easy to see an entire broker at a glance, it's free, it runs on macOS, Windows, and Linux, and it's especially popular in the Home Assistant and hobbyist communities. If you've used it, that point-and-click way of browsing topics will feel second nature.

MQTT Viewer is built in the same spirit — a visual, approachable way to explore a broker — so moving over is easy. The difference is what it adds around that familiar tree.

How MQTT Viewer is different

MQTT Viewer keeps the topic tree you already know and layers on capabilities for day-to-day debugging:

  • Up to 10 connections at once. Keep development, staging, and production brokers open side by side instead of one at a time.
  • An interactive message timeline. Scrub back through a topic's history to see exactly what was published and when.
  • Message comparison. Diff two payloads to spot precisely what changed.
  • Built-in payload decoding. Read Sparkplug B (protobuf), Base64, and Hex payloads without leaving the app.
  • Full MQTT v3.1.1 and v5 over TCP, TLS/SSL, mutual TLS, and WebSocket, with username and password authentication.
  • A fast, native app for macOS, Windows, and Linux that's actively developed and free and open-source under GPL-3.0.

Making the switch is easy

Because the mental model is the same, there's almost nothing to relearn. You connect to your broker, watch the topic tree fill in, and drill into any branch — then reach for the timeline, filters, and decoders when you need them. MQTT Viewer is free, installs in seconds, and needs no account.

Frequently asked questions

Is MQTT Viewer similar to MQTT Explorer?

Yes. MQTT Viewer keeps the familiar hierarchical topic tree that made MQTT Explorer so popular, so it feels instantly familiar, and adds an interactive message timeline, message comparison, and payload decoding on top.

Is MQTT Viewer free and open source?

Yes. MQTT Viewer is completely free and open-source under the GPL-3.0 license, with no account or sign-up required.

Can MQTT Viewer connect to several brokers at once?

Yes. MQTT Viewer supports up to 10 simultaneous broker connections, so you can keep development, staging, and production open side by side.

Is MQTT Viewer actively developed?

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

Want to see the wider landscape? Browse the best MQTT clients overview, or just download MQTT Viewer for macOS, Windows, or Linux.

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

Download MQTT Viewer