KML (Keyhole Markup Language)
KML is an XML-based format for displaying geographic data in Google Earth, Google Maps, and other mapping applications. It supports placemarks, paths, polygons, 3D models, image overlays, and animated tours.
MIME Type
application/vnd.google-earth.kml+xml
Type
Text
Compression
Lossless
Advantages
- + Rich visualization — 3D models, tours, image overlays
- + OGC standard with broad mapping tool support
- + KMZ compression reduces file sizes for complex projects
- + Native support in Google Earth and Google Maps
Disadvantages
- − Primarily visualization-focused — not for geospatial analysis
- − Verbose XML syntax for complex features
- − GeoJSON is simpler and more common for web mapping
When to Use .KML
Use KML for Google Earth presentations, geographic data visualization, and sharing map layers with placemarks and overlays.
Technical Details
KML uses XML with geographic elements: Placemark, Point, LineString, Polygon, and GroundOverlay. Coordinates are WGS84 in longitude,latitude,altitude order. KMZ is the compressed (ZIP) variant of KML.
History
Keyhole Inc. developed KML for its EarthViewer 3D application. Google acquired Keyhole in 2004 (renamed to Google Earth), and KML became an OGC (Open Geospatial Consortium) standard in 2008.