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
Install PX4 ULog Viewer from the VS Code Marketplace.
Open a folder containing a .ulg or .ulog log file.
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 —
Shift+click a field to add every visible field between it and the last
one you clicked. 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. The Topics button in the plot toolbar collapses the
topic list to give the plots the full width. If the log contains raw GNSS
communication (gps_dump, enabled with GPS_DUMP_COMM), it is decoded
into per-direction protocol message counts (UBX, RTCM3, NMEA, SBF) shown
under the topic, and each message type gets a plottable "gap" series —
seconds since that type's previous frame — for spotting periods where a
message stopped arriving. Message contents are not decoded; to inspect
them, extract the raw streams with pyulog's ulog_extract_gps_dump and
use a protocol tool such as u-blox u-center.
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.
Press Ctrl+F (Cmd+F on macOS) on any tab to jump to its search box: the
topic filter on Data, the parameter and message filters on their tabs, and
a content filter on Info and Structure.
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.
