Free online TCX to GDB converter

What the TCX format is

TCX, or Training Center XML, is an XML-based fitness format used for GPS activities such as rides, runs, and walks. It can store timestamps, coordinates, distance, speed, elevation, heart rate, cadence, laps, and activity metadata. Garmin Training Center and Garmin devices created many TCX files; Garmin Connect, Strava, and other fitness platforms may also export them. A TCX file is human-readable XML, so it is easy to inspect but generally larger than a binary database file.

What the GDB format is

GDB is Garmin’s binary database format associated with MapSource and supported by some Garmin desktop workflows, including compatible BaseCamp operations. It is intended to store Garmin map data objects such as waypoints, routes, and tracks in a compact database. GDB is useful when Garmin software requires or handles that database format, but it is less portable than GPX and does not necessarily preserve every fitness-specific TCX field.

How to actually convert TCX to GDB

GPSBabel is the most practical desktop option because it supports Garmin Training Center XML input and Garmin MapSource GDB output.

1. Install GPSBabel for your operating system.
2. Open GPSBabel and select Input format → Garmin Training Center XML.
3. Select the source .tcx file.
4. Select Output format → Garmin MapSource - GDB.
5. Choose an output filename ending in .gdb and start the conversion.

From a command line, the equivalent conversion is:

gpsbabel -i tcx -f activity.tcx -o gdb -F activity.gdb

Replace activity.tcx with the input path and activity.gdb with the desired output path. For multiple files, convert them separately or combine them as GPSBabel inputs when the resulting database structure is appropriate.

You can also use the free converter on 101convert.com without installing software: upload the TCX file, select GDB as the target format, run the conversion, and download the resulting file.

Quality and compatibility limits

TCX records training details that do not map cleanly to GDB. Track coordinates, timestamps, routes, and waypoints are the most likely data to survive; heart-rate samples, cadence, power, lap structure, calories, and device-specific metadata may be discarded or simplified. Open the result in the intended Garmin application and verify the track, time information, and route before deleting the original TCX.

Because GDB is a Garmin-specific binary format, use GPX instead when the converted data must work across mapping, fitness, or GIS applications. Keep the original TCX as the lossless source file for later reprocessing.