GPX vs TCX vs FIT — Which Format Should You Use?
Published: August 2026 · 7 min read
If you have ever exported a ride from one app and tried to import it into another, you have probably encountered the alphabet soup of GPS file formats: GPX, TCX, FIT, KML, and CSV. This guide explains the three most important ones — GPX, TCX, and FIT — and helps you pick the right format for your use case.
| Format | Type | Best for | Lap support |
|---|---|---|---|
| GPX | XML, open standard | Routes, navigation, sharing | Via segments |
| TCX | XML, Garmin | Structured training data | Native <Lap> |
| FIT | Binary, Garmin | Complete activity records | Native |
GPX — the universal exchange format
GPX (GPS Exchange Format) is the most widely supported GPS format. Every major mapping tool, fitness platform, and navigation device can read and write GPX. It is human-readable XML, which means you can open it in a text editor, inspect it, and even fix problems by hand.
Use GPX when you need to share a route with someone who uses different software, or when you want to archive your data in a future-proof, non-proprietary format. GPX is also the best format for route planning — creating a path you intend to follow before you ride.
Limitations: GPX does not natively support lap elements, heart rate, cadence, or power data (though some extensions exist). If you care about splitting a recording into laps with lap times, you need the Lap Detector to add segment boundaries.
TCX — Garmin Training Center XML
TCX (Training Center XML) was developed by Garmin as an extension of GPX that adds training-specific data. The key advantage over GPX: TCX has a native <Lap> element. Each lap in a TCX file carries a start time, total time, distance, intensity, and trigger method. This makes TCX the ideal format for structured workouts and interval sessions.
Use TCX when you want your laps to be explicitly labelled and preserved when you import into Garmin Connect, TrainingPeaks, or Golden Cheetah. The GPX Tools export supports TCX output with proper <Lap> elements.
Limitations: TCX is not as widely supported as GPX. Platforms like Komoot, RideWithGPS, and many route planners do not accept TCX. Some modern Garmin devices have dropped TCX support in favour of FIT.
FIT — the binary powerhouse
FIT (Flexible and Interoperable Data Transfer) is a compact binary format developed by Garmin. Unlike the XML-based GPX and TCX, FIT stores data in a structured binary stream that is far more space-efficient — a 200 km ride might be 50 MB as GPX but 2 MB as FIT.
FIT is the native format of modern Garmin watches and bike computers. It preserves everything the device records: GPS points, heart rate, cadence, power, temperature, gear shifts, and even device battery level. Strava, TrainingPeaks, and Garmin Connect all support FIT.
Limitations: FIT is a complex binary format. You cannot open it in a text editor, and producing valid FIT files requires specialized software. For most users, GPX or TCX is the practical choice for editing and sharing. FIT export is planned for a future release of GPX Tools.
Need to convert between formats? Use GPX Tools to process your track and export it as GPX, TCX, KML, CSV, or GeoJSON depending on where the file will be used next.
Try GPX Tools →← All articles · Read next: Recording Perfect GPS Laps