For training apps and older tools that only speak TCX. Free. No signup. Nothing stored.
TCX requires an activity/lap structure that GPX doesn’t have, so the tool wraps your track in a single lap with total time and distance computed from the points. Heart rate and cadence in Garmin GPX extensions are carried into their native TCX elements.
Your file is never written to disk. It is parsed in memory, converted, sent back, and garbage-collected. No accounts, no tracking pixels, no “files are deleted after 24 hours” fine print — there is nothing to delete.