File formats

A GPX file is a text file for GPS data. It holds recorded tracks, planned routes and waypoints, and hundreds of apps and websites can open it.

A KML file is a text file that describes what to show on a map or a globe, such as places, lines and areas, with their colours and icons. It was made for Google Earth and is now an open standard of the Open Geospatial Consortium (OGC).

A KMZ file is a KML file packed in a ZIP archive, usually together with the icons and images the map uses. It holds the same data as KML in a smaller file.

A FIT file is a compact binary file for data from sport, fitness and health devices, such as a recorded run or ride with its GPS positions, heart rate, power and laps. Garmin designed the format and publishes it with a free SDK.

A TCX file stores a workout as XML text, with laps and their totals, and track points with time, position, heart rate and cadence. Garmin defined the format, and training services such as Strava still accept it.

Use GPX to move a track or a route between GPS apps and devices. Use KML to show places, lines and areas in Google Earth or on a map, with your own colours and icons.

Use TCX when the workout matters, because laps, heart rate and cadence are part of the format. Use GPX for routes, waypoints and maps, because more apps read it.

A KMZ file is a KML file packed in a ZIP archive, often with the images and icons it uses. The data is the same. Use KMZ to send a file with its pictures or to make it smaller, and KML to read or edit the text.