MQTT Viewer changelog

1.2.0 October 2026

What's new in MQTT Viewer 1.2. Sparkplug metric names, a live network view and expandable pinned topics.

Added

• Broker status in the browser. Open Broker status from the view selector in Docker and Home Assistant.
• A live view of your Sparkplug network. Inspect groups, nodes, devices and metrics with warnings and rebirth requests.
• Improved Sparkplug B decoding. Sparkplug decoding resolves NDATA and DDATA aliases to metric names. Thanks adamwoodland2 and thebaldgeek.
• Expandable pinned topics. Expand pinned branches, filter them with search and resize the pinned block. Thanks mrpiggi.

Fixed

• Crash when decoding Sparkplug on MQTT 3 connections. Thanks CantDecodeMe.
• Repair unencrypted saved passwords. Unchanged passwords were saved unencrypted; startup now repairs them, but some long passwords resembling encrypted data need changing once. Thanks viktak for the logs that led to this.
• Windows updates across drives. From 1.1.0 or earlier, download this version manually once. Thanks viktak.
• Updates from protected Windows folders. Installs under Program Files now link to the download instead of trying to update themselves.
• New messages no longer stick at "Loading message...". Thanks ejannink and Noschvie.
• Deleting a connection no longer mixes up the other tabs.
• Panels keep their width when you switch views.
• Window buttons line up with the tab bar on macOS.
• Startup failures show an error instead of a blank window.
• The Nix flake builds again. Thanks sikmir.
• Connection failures show readable errors.
• The Docker image stops promptly. Shutdown waits at most 5 seconds for in-flight HTTP requests, down from 30.
• The topic tree no longer goes blank when it shrinks.
• Topics named like toString or constructor show up.

Miscellaneous

• Wails desktop shell updated to beta.16.

Found a bug? Let me know through the Feedback button.

Downloads and checksums for 1.2.0 are on the GitHub release, or get the latest from the download page.

1.1.0 September 2026

What's new in MQTT Viewer 1.1. A graph view of your topics, a broker status page, retained-message cleanup, and the whole app in a browser. Plus two months of fixes.

Added

• See your topics as a graph. Each node is sized and coloured by its traffic. Switch between list and graph above the tree.
• Pin the topics you keep coming back to. Pin a topic from its right-click menu and it stays at the top of the tree, per connection. Thanks mrpiggi.
• Sort topics by how busy they are. Busiest first, most messages, newest first or silent first, in the list and the graph.
• Right-click a topic. Copy the path or payload, export history, or clear the retained message. Thanks Daschi2.
• Clear retained messages in bulk. Right-click a branch to clear every retained message beneath it. The confirmation lists exactly what will go. On MQTT 3 only messages this client has seen can be cleared. Thanks Daschi2.
• Spot retained topics at a glance. Retained topics carry a small marker in the list and the graph.
• A status page for your broker. Health warnings, a traffic chart and the loudest topics, from $SYS on mosquitto, EMQX and VerneMQ, with client-side rates for brokers that publish nothing. Thanks m1dnight, adamwoodland2 and viktak.
• Run MQTT Viewer in your browser. A Docker image, ghcr.io/mqtt-viewer/mqtt-viewer, and a Home Assistant add-on. Setup is in docs/DOCKER.md. Thanks SiriosDev.
• See what the MQTT client is doing. View logs in the connection menu shows connects, subscriptions and errors live, with debug logging per connection.
• Rearrange the panels. The topic panel docks right or bottom, or pops out into its own window. Thanks ElectronicBattle.
• Better collection controls and interactions. New message from any folder, drag to reorder or move between folders, drag history entries in, rename by clicking the name.
• Peek at messages on the timeline. Hover a marker for the payload, time, QoS and retained flag. Thanks Daschi2.
• Pick your own chart time window. 3, 6 and 12 hours, a day, or a custom interval. Thanks viktak.
• Windows on ARM. A native ARM64 build with installer and auto-updates. Thanks cbulock.
• A Flatpak for Linux. With its own auto-updating repository. Thanks maracuya-robotics.
• Install it with Nix. A flake for x86_64 and aarch64 Linux.

Changed

• Chart values that arrive as text. A number in quotes charts like a plain one. Thanks andyg2 and Stefan-Pichler.
• Adding a value to a chart is clearer. "Add value from payload" opens the picker on the value. Thanks Daschi2.
• Clearer memory settings. Settings show what history is using and what the app can grow to per connection.
• The memory budget now covers every topic. The last value kept per topic counts against it.
• Icon seed and delete are out in the open. At the top of the connection form instead of behind a cog.
• A tidier sidebar and forms. Rows and icons share a grid, and fields no longer crowd their labels.

Fixed

• Connection failures were reported late and vaguely. On MQTT 3 a bad host, port, credential or certificate now fails immediately with a plain reason.
• Reconnecting when the network drops out. MQTT 5 connections notice a silent broker within about ten seconds and keep retrying.
• Two connections to the same broker no longer fight. Each gets its own client ID.
• WebSocket paths. Connections with a path like /mqtt connect again. Thanks mfried40.
• Deleting a connection. No longer fails if it had history, and clearing a large history no longer freezes the app.
• Crash when disconnecting from a busy broker.
• Message counts under load. The counters no longer drop messages.
• Message order on MQTT 3. Recorded in arrival order, as on MQTT 5.
• The chart's Y-axis rescales with its time window.
• Chart and dropdown fixes. "All history" no longer sticks; Windows dropdowns no longer open as a sliver. Thanks viktak and Stefan-Pichler.
• Pop-out windows can be moved.
• Dropdowns inside dialogs open on top, not behind.
• The timeline reaches every message in loaded history.
• Light mode. Charts, the timeline and icons follow the theme.
• The interface font loads again.

Miscellaneous

• Connect and disconnect from the connection dialog's header.
• The connection dialog has a Save button. Thanks jeeftor.
• The pencil on a connection tile opens the details dialog.
• Long topic previews truncate at the panel edge.
• The main window no longer scrolls by a phantom line.
• Buttons with tooltips take one tab stop, not two.
• Dependencies updated to close 19 security issues.

Found a bug or a rough edge? Use the Feedback button, I want to know.

Downloads and checksums for 1.1.0 are on the GitHub release, or get the latest from the download page.

1.0.0 July 2026

MQTT Viewer 1.0 is here. After years of betas, MQTT Viewer is officially 1.0. The big new features (charting, collections, bounded memory, image previews) arrived in 0.7.0, so have a look at that tab too. Here's what 1.0 adds on top.

• Release notes. After each update you'll see a short summary of what changed, like this one. You can reopen it any time from Settings, or by clicking the version number at the bottom of the window.
• Linux fixes and auto-updates. There are proper rpm and deb packages now, so Fedora no longer crashes at startup. AppImages render correctly again, and the app can update itself. Thanks hobbes1069.

Found a bug or a rough edge? Use the Feedback button, I want to know.

Downloads and checksums for 1.0.0 are on the GitHub release, or get the latest from the download page.

0.7.0 July 2026

What's new in 0.7.0. A big one: charting, collections, bounded memory, image previews, and a new engine under the hood.

• Light mode. The app now has a proper light theme, with a toggle that remembers your choice. Thanks oeed and juggledad.
• Topic charting. Chart numeric payload fields over time, live, with a pop-out window. Thanks edolis.
• Message library. Collections of saved messages, publish history, and search, all in the new sidebar. Thanks viktak.
• Bounded memory and durable history. History stays within a configurable memory budget, with opt-in recording to disk. Thanks m1dnight.
• Image payload previews. Image payloads render as images, not noise. Thanks jeeftor.

Downloads and checksums for 0.7.0 are on the GitHub release, or get the latest from the download page.