How KML works
KML describes Placemarks, geometries (points, lines, polygons), and their presentation using an XML tree that also supports folders for organization, rich styling (icons, colors, line widths, fills), balloon descriptions, and ground overlays. It is designed for display and sharing rather than analysis, and is opened natively by Google Earth, Google Maps, and most GIS packages. Because it targets a single global view, it has no concept of reprojection.
Coordinate systems and reprojection
KML coordinates are always geographic WGS84 longitude, latitude, and (optionally) altitude in that order; the format has no CRS or projection field, so any data written to KML is expressed in EPSG:4326 by definition.
Compare KML with other GIS formats
Convert KML to another format
Choose a conversion below for the online converter, format-specific caveats, and step-by-step instructions for KML.
Convert files to KML
Frequently asked questions
- What file extension does KML use?
- KML uses .kml.
- Does KML store a coordinate system?
- KML coordinates are always geographic WGS84 longitude, latitude, and (optionally) altitude in that order; the format has no CRS or projection field, so any data written to KML is expressed in EPSG:4326 by definition.
- Can I convert KML online?
- Yes. GeoConvert can read or write KML in your browser for the conversion paths listed above, without uploading free-tier files to a server.