KML was designed for Google Earth visualization, GPX for GPS devices and trackers. Both store geodata but for different purposes.
| Criteria | KML | GPX |
|---|---|---|
| Google Earth | ✓ | ✗ |
| GPS devices | ✗ | ✓ |
| Styles & colors | ✓ | ✗ |
| Waypoints/tracks | ✓ | ✓ |
| Simplicity | ✗ | ✓ |
For Google Earth visualization, presentations, rich styling.
For GPS devices (Garmin), trekking, sports applications.