How to Convert Fitness Files Online — Free & Private
Whether you train with a Garmin watch, a Wahoo head unit, or a Suunto device, your workouts are stored in proprietary formats. RaaConnect's free file converter lets you switch between FIT, TCX, GPX, and CSV formats without uploading anything to a server. Every conversion runs entirely inside your browser using WebAssembly and the Web File API.
What is a FIT file?
The Flexible and Interoperable Data Transfer (FIT) protocol is a binary format developed by Garmin. It is the richest fitness data format, storing GPS coordinates, heart rate, cadence, power, temperature, HRV, and dozens of device-specific metrics in a compact binary file. Garmin Connect, Wahoo, Suunto, and Zwift all use FIT.
FIT vs GPX vs TCX — which format to use?
- FIT — best for storage and analysis. Richest data. Required for Garmin Connect import.
- GPX — best for sharing routes. Widely supported by Strava, Komoot, Google Maps, and hiking apps.
- TCX — best for heart rate and cadence across older platforms like Polar Flow and Fitbit.
- CSV — best for data science, custom charts, and spreadsheet analysis.
Is my data safe?
Yes. All conversion logic runs as JavaScript in your browser tab. Your file is read via the FileReader API and never transmitted over the network. There are no server uploads, no accounts, and no tracking of file contents.