Chart MQTT payload values live

Tick the numeric fields you want in the payload tab and they plot live in the Chart tab.

Try it in MQTT Viewer

A line chart of a temperature field from a JSON payload, with the time window menu open showing options from 5 minutes to 1 day and a custom interval

What can be charted

  • Any numeric field in a JSON payload, nested or not.
  • Payloads that are a bare number.
  • Numbers sent as strings, such as "24.6".
  • Values with a decimal comma, read as decimals rather than thousands.

Series and drawing

Each series has a colour, a legend entry, a hide toggle and a remove button. Long histories are downsampled for drawing.

Time windows

5, 15 or 60 minutes, 3, 6 or 12 hours, a day, all history, or a custom interval. Pause freezes the chart while messages keep arriving.

Pop-out windows

Send a chart to its own window. Open several to build an ad hoc MQTT dashboard.

A chart in its own pop-out window, plotting two fields from the same topic

Frequently asked questions

Can MQTT Viewer chart values sent as strings?

A field that holds a number in quotes, such as "24.6", charts as a number. Fields that do not parse as numbers are not offered in the picker.

Can MQTT Viewer chart several topics on one graph?

A chart shows one topic with as many of its fields as you tick. To watch several topics, open each in a pop-out chart window.

Related features

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

Download MQTT Viewer