Files: GPX, FIT and TCX

The three files a watch or an app gives you, explained from the inside: what a GPX, FIT or TCX actually contains, which to send where, how to open, convert, repair and upload them, and what to do when the elevation is wrong or Strava says no.

How-to · 07.09.2026

Repair a FIT file that will not upload

A FIT file gets refused when the watch lost power, the transfer stopped early or the timestamps went wrong. Which tools repair which fault, how to check the file first, and when the original on Strava is the better route.

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Repair a FIT file that will not upload

How-to
23.08.2026

GPX, FIT or TCX — which file should you send?

Three formats, one job. What each of them actually stores, which one your watch produces, and why it does not matter as much as...