What is a TCX file?

What TCX is

TCX is a plain-text format you can open in any editor. It is used for fitness tracking.

The extension is .tcx, and the full name is Training Center XML. Both matter less than what the file can hold, which is what the rest of this page is about.

Where TCX came from

Garmin published it in 2007. The specification is Training Center XML.

Age is worth knowing here for one practical reason: the older a format is, the more programs have had time to learn it.

The specification is published, but by its owner

It is written down and implementable, though the vendor decides what the next version looks like. In practice that is enough for the file to keep opening; it is not enough to be sure of it.

Nothing is thrown away

TCX stores its content exactly. Saving it again changes nothing, so it can be opened, edited and re-saved as often as you like without accumulating damage — which is what makes it a working format rather than a delivery one.

What opens TCX

Garmin Connect, Strava and TrainingPeaks read it, and so do most programs of the same kind.

If a file will not open, the format is rarely the problem — it is more often that the program predates it. Converting to something older is the reliable way past that, and it is what the rest of this site is for.

Opening it in a browser

No browser reads it.

That is the single most common reason to convert it: not that the format is bad, but that the place you want to show the file cannot read it.

It is a working format

TCX is meant to be opened and changed. Keep the file in this format for as long as the work is going on, and export from it whenever a finished copy is needed.

The facts, in one place

Converting TCX to something else

• TCX to CSV
• TCX to GPX
• TCX to KML
• TCX to KMZ

Converting something else to TCX

• GPX to TCX
• KML to TCX
• KMZ to TCX

Formats worth considering instead of TCX

• GPS Exchange Format
• Flexible and Interoperable Data Transfer