About

GPX Converter is an independent toolbox for the three file formats every athlete and route-planner ends up juggling: Garmin's FIT, the universal GPX, and Training Center TCX. It converts between them, merges and splits activities, repairs a damaged FIT file, and previews any track on a map — without an account, without a queue, and without your files ever leaving your device.

Everything here runs as client-side JavaScript. When you drop a file, a Web Worker on your own machine parses the bytes, does the conversion and hands you back the result directly. There is no upload endpoint to send data to and no server-side storage — by architecture, not by policy. That matters for GPS files especially: a training log is a detailed record of where you live, where you go and when.

The project started the way most good tools do — with a corrupted .fit file, a refused upload and an evening lost to desktop software. The browser turns out to be a perfectly capable GPS file workbench; it just needed someone to build the bench.