How It Works
When you load a GPX or FIT file into GPXFIT, the file is read and processed using JavaScript running in your web browser. All the parsing, editing, analysis, and export operations happen locally on your computer or device. We don't have servers that receive or store your activity files.
This means your routes, GPS coordinates, heart rate data, power data, and any other information in your files remains private and under your control at all times.
Third-Party Services We Use
While your files are processed locally, GPXFIT does make requests to external services for certain features. Here's what data is sent and when:
| Service | What It's Used For | What Data Is Sent |
|---|---|---|
| OpenStreetMap | Map tiles for 2D route visualization | Map tile coordinates only (e.g., zoom level, tile X/Y position). Your actual route coordinates are not sent - only which map tiles need to be displayed. |
| MapTiler | 3D terrain visualization and outdoor map tiles for the 3D View tool | Map and terrain tile coordinates only. Similar to other map services, only tile positions are requested, not your route data. An API key is used to authenticate requests. |
| Open-Elevation API | Elevation data lookup for the Elevation Check tool | Sampled GPS coordinates (up to 100 points from your route) when you use the "Compare with API" or "Replace Elevation" features. This is the only service that receives any of your actual route coordinates. |
Local Storage
GPXFIT uses your browser's local storage to remember your preferences, such as:
- Theme preference (light/dark mode)
- Your FTP (Functional Threshold Power) setting
- Your LTHR (Lactate Threshold Heart Rate) setting
- Your Max HR (Maximum Heart Rate) setting
- Your weight setting
- Custom best effort durations for analysis tools
- Your MapTiler API key (if you provide your own)
This data is stored only in your browser and is never sent to us or any third party. You can clear this data at any time by clearing your browser's local storage for this site.
No Tracking or Analytics
GPXFIT does not use any analytics services, tracking pixels, or cookies to monitor your usage. We don't collect any information about how you use the app, which files you edit, or any other behavioral data.
Open Source
GPXFIT's code is transparent. You can inspect exactly what the application does and verify these privacy claims for yourself.