GPX vs FIT: Understanding the Difference

FIT (Flexible and Interoperable Data Transfer) is the binary format developed by Garmin and used by most modern GPS watches and bike computers. Unlike GPX, a plain-text (XML) format you can read directly, FIT is compact and binary-encoded, more efficient to store and transmit, but unreadable without dedicated software.

When to use GPX

GPX remains the most universally understood format: nearly every GPS app, route- sharing site, and mapping tool accepts it as input.

When to use FIT

FIT is what a Garmin device (and many other brands) natively produces after recording an activity. If you need to import a recording directly into sport-focused software (Garmin Connect, TrainingPeaks…), FIT is often the expected format.

Converting between them

• FIT → GPX, to reuse a recorded activity as a route in a regular GPS app.
• GPX → FIT, to import a planned route into a device or service that expects FIT.

Note: our GPX → FIT converter targets a minimal "running activity" profile, without computed aggregates like total distance or calories, which can't be reliably fabricated from a plain route.