KML and Google Earth
Last updated: 2026-02-20 · Format Guides
What is KML?
Keyhole Markup Language (KML) is an XML-based format originally developed for Google Earth. It's now an OGC standard for displaying geographic data in earth browsers and mapping applications.
KML vs KMZ
- KML: Plain XML text file. Human-readable and editable.
- KMZ: A ZIP archive containing a KML file plus any referenced images, icons, or overlays. More compact and self-contained.
Key Characteristics
- CRS: KML requires WGS 84 (EPSG:4326). Data in other projections must be reprojected.
- Styling: KML has built-in styling support — colors, icons, line widths, polygon fills.
- 3D support: Includes altitude modes (clampToGround, relativeToGround, absolute) for 3D visualization.
- Time support: TimeSpan and TimeStamp elements enable temporal visualization in Google Earth.
Converting KML
ConvertGeoData extracts geometry and attributes from KML/KMZ files and converts to any supported vector format. Styling information is preserved where the target format supports it.
Popular conversions: KML to GeoJSON, KML to Shapefile, KMZ to GeoJSON.