PX4 ULog Viewer

Open and inspect PX4 ULog flight logs (.ulg and .ulog) directly in VS Code. The extension replaces the binary file view with an interactive log viewer for quick flight-data inspection.

Getting started

1. Install PX4 ULog Viewer from the VS Code Marketplace.
2. Open a folder containing a .ulg or .ulog log file.
3. Open the log file from the Explorer, or select the ULog Viewer icon in the Activity Bar and choose a file from the list.

You can also run ULog Viewer: Open ULog File from the Command Palette to open a log from anywhere on disk.

Explore a flight log

The viewer provides the following sections:

• Data: browse logged topics and select numeric fields to chart them. Add plot panels to compare signals; their time axes stay synchronized. Drag to zoom, double-click a chart, or select Reset zoom to restore the full time range.
• Replay: replay the flight trajectory from a log on a 2D top-down map with HUD overlay showing critical flight data.
• Info: review log metadata, duration, software and hardware versions, and information entries recorded by the vehicle.
• Parameters: search logged parameters and inspect any values that changed during flight, including their timestamped history.
• Messages: view the onboard log console, including PX4_INFO, PX4_WARN, and PX4_ERR messages.
• Structure: inspect the raw ULog file internals like file layout and section sizes, compatibility flags, message-type and log-level counts, all format definitions, every logged subscription, and any dropout events.

Supported files

PX4 ULog files with .ulg and .ulog extensions are supported. Logs remain on your machine; the extension reads them locally in VS Code.

License

Copyright 2026 Anil Kircaliali. All rights reserved.