FIT (Flexible and Interoperable Data Transfer) is the native format used by Garmin, Wahoo, and most modern cycling computers and GPS watches. While it's efficient and stores more data than GPX, it's a binary format — you can't open it in a text editor, many apps don't accept it, and sharing or archiving raw data is awkward.

Converting to GPX or another open format solves all of this.

When You Need to Convert a FIT File

An app or website only accepts GPX (not FIT)
You want to open your activity data in a spreadsheet (CSV)
You're archiving workouts in a readable format
You need to import a Garmin activity into a non-Garmin platform
You want to inspect your raw activity data (JSON)

Supported Output Formats

Stamptivity's Convert tool supports four output formats:

Format	Best for
GPX	Universal GPS format, accepted by nearly every mapping and fitness app
TCX	Training-focused format used by Garmin and some older platforms
JSON	Developers, data analysis, custom scripts
CSV	Spreadsheets, Excel, Sheets — one row per GPS point with all fields

Step-by-Step: Convert FIT to GPX

1. Get Your FIT File

FIT files are stored on your device's memory card, or you can export them from:

Garmin Connect — open the activity, click the gear icon (⚙), select Export Original. This downloads the .fit file, not the processed GPX.
Wahoo — connect your ELEMNT to a computer via USB and browse to the activities folder on the device.
Coros — open the activity in the Coros app, tap Share → Export, and choose FIT.

2. Open the Convert Tool

Go to Stamptivity Convert and drop your .fit file onto the upload zone, or click to browse.

The tool reads the file entirely in your browser — nothing is uploaded to any server.

3. Choose a Format

Select your output format from the dropdown:

Choose GPX for maximum compatibility
Choose CSV if you want to open the data in Excel or Google Sheets
Choose JSON if you're piping it into another script or tool

4. Download

Click Download and your converted file saves immediately.

What Data Is Preserved?

The converter carries over:

GPS coordinates — latitude, longitude, altitude
Timestamps — full date and time for each point
Speed — from the device sensor or calculated from position
Heart rate — if you used a chest strap or optical HRM
Cadence — for cycling and running activities
Power — for cycling activities with a power meter
Temperature — if your device recorded it

What About FIT Files Without GPS?

Indoor activities (trainer rides, treadmill runs) have no GPS coordinates, so GPX and TCX exports will contain only the non-spatial fields. CSV and JSON still export the full timeseries data including power, cadence, and heart rate — useful for analysis.

Tips

If you need a GPX for Stamptivity Stamp (to create a stats photo), converting your FIT first is the quickest path — then drop the GPX into the Stamp tool.
The CSV format is the most useful for data analysis — each row is one GPS point, columns include all recorded fields.
If your FIT file came from a multi-sport activity (triathlon), the converter processes all segments as a continuous track.

How to Convert a FIT File to GPX, TCX, JSON, or CSV