GPXFIT

File Formats

GPXFIT supports GPX, FIT, and GeoJSON file formats, allowing you to work with files from virtually any GPS device, application, or mapping platform.

Supported Formats

GPX (GPS Exchange Format)

GPX is an open XML-based format for GPS data. It's widely supported by:

  • Mapping applications (Google Maps, Komoot, Strava)
  • GPS devices (Garmin, Wahoo, Coros)
  • Fitness platforms (Strava, TrainingPeaks)
  • Route planning tools

What GPXFIT preserves from GPX files:

  • Track points (coordinates, elevation, timestamps)
  • Waypoints
  • Routes
  • Metadata (name, description)
  • Garmin extensions (heart rate, cadence, temperature, power)

FIT (Flexible and Interoperable Data Transfer)

FIT is Garmin's binary format used by most modern fitness devices. It's more compact than GPX and includes richer metadata.

What GPXFIT extracts from FIT files:

  • All track points with coordinates and timestamps
  • Elevation data
  • Sensor data (heart rate, cadence, power, temperature)
  • Activity type (cycling, running, hiking, etc.)
  • Device information (manufacturer, model)
  • Speed and distance data

GeoJSON

GeoJSON is an open standard format for representing geographic data based on JSON. It's commonly used by web mapping libraries and GIS applications.

What GPXFIT supports in GeoJSON:

  • LineString geometry (track points)
  • MultiLineString (tracks with segments)
  • Point features (waypoints)
  • FeatureCollection (mixed tracks and waypoints)
  • Coordinate property arrays (timestamps, heart rate, power, etc.)

Coordinate Property Arrays:

GPXFIT follows the Mapbox convention for per-point data in GeoJSON properties. When exporting, sensor data is stored as arrays that align with the coordinate array:

  • times[] - ISO 8601 timestamps
  • heartRates[] - Heart rate values
  • powers[] - Power values
  • cadences[] - Cadence values
  • temperatures[] - Temperature values
  • speeds[] - Speed values

Import

To import a file:

  1. Click the upload area or drag and drop your file
  2. GPXFIT automatically detects the format (.gpx, .fit, .geojson, or .json)
  3. The file is processed entirely in your browser - no upload to servers

Export

After editing your track, you can export to:

  • GPX - Universal format, compatible with all platforms
  • FIT - Garmin format, preserves all sensor data
  • GeoJSON - Web mapping format with configurable options
  • CSV - Spreadsheet format for data analysis

GeoJSON Export Options

When exporting to GeoJSON, you can choose what data to include:

  • Elevation - Include elevation as the 3rd coordinate
  • Timestamps - Include time data in the times property array
  • Heart Rate, Power, Cadence, etc. - Include sensor data arrays
  • Waypoints - Include waypoints as Point features
  • Pretty print - Format with indentation for readability

Format Conversion

GPXFIT can convert between any supported formats:

  • FIT → GPX: Import a FIT file, export as GPX
  • GPX → FIT: Import a GPX file, export as FIT
  • GPX/FIT → GeoJSON: Export for use in web mapping applications
  • GeoJSON → GPX/FIT: Import GeoJSON and export to GPS formats

When converting GPX to FIT, GPXFIT creates a valid FIT file structure. Note that some FIT-specific data (like original device info) won't be present unless the source was a FIT file.

Tips

  • FIT files typically contain more metadata (device info, activity type)
  • GPX files are more portable and human-readable
  • GeoJSON files are ideal for web mapping and GIS applications
  • All editing tools work identically regardless of source format
  • Sensor data (HR, power, cadence) is preserved when present