Choose an activity file
Open one .fit, GPX 1.1 .gpx or TCX v2 .tcx file.
Explore activity data on your device.
Activity File to JSON
Export a normalized FIT, GPX or TCX activity model with points, available metrics, laps and source limitations as JSON.
Unknown FIT developer fields and unsupported GPX or TCX extensions are not included.
Activity File ViewerYOUR WORKSPACE
Your task
Download JSON
Choose a file, then use Download JSON to save the result.
Also with this file: View activity · Download CSV · Download Excel · Download GPX
Processed privately in your browserNo uploadNo signup
A simple workflow
Three steps. One less thing to do.
Inspect the track
Review summary metrics, laps, point rows and a local track outline.
Export the useful fields
Save CSV, Excel, JSON or a GPS-only GPX track.
Made for the everyday
A useful part of your workflow.
Fitness export review
Inspect timestamps, distance and sensor metrics before moving the data.
GPS track inspection
Read a route and elevation values without signing in to a map service.
Spreadsheet analysis
Export point rows and lap summaries to CSV or Excel.
Good to know
A few useful answers.
The details that matter before you use Activity File Viewer.
Which formats are supported?
FIT files with valid CRC, GPX 1.1 tracks/routes/waypoints and one-activity TCX v2 files are supported.
Does a map provider receive my coordinates?
No. The track outline is a local SVG, without external tiles or geocoding.
Are FIT developer fields included?
No. The parser handles standard records but unknown and developer-defined fields are outside the normalized export.
What does GPX export preserve?
Coordinates, elevation and timestamps where present. Heart rate, power, cadence and laps are omitted from GPX.
Are missing metrics calculated?
No. Absent source metrics remain empty; GPX distance and duration are not inferred.
Does the file leave my device?
No. Parsing and exports run in the browser. GPS coordinates and activity details are excluded from analytics.
What are the limits?
Files up to 5 MB are supported, with at most 20,000 track points and 500 FIT laps. Larger files or FIT activities above these limits fail clearly; laps are never silently omitted.