KML (Keyhole Markup Language) is an OGC standard XML grammar for expressing geographic annotation and visualization. It is used to display features such as placemarks, paths, and overlays in earth browsers and mapping tools.
KML
KML, or Keyhole Markup Language, is an XML grammar for expressing geographic annotation and visualization, adopted as an Open Geospatial Consortium (OGC) standard in 2008 after originating with Google Earth. It describes points, lines, polygons, images, and camera views so that geographic features can be shared and rendered consistently across earth browsers and mapping tools. Because it is plain XML, KML travels well between systems and is easy to generate, transform, and validate.
- Placemarks and geometry - Points, paths, and polygons with coordinates, styling, and descriptive metadata.
- Ground and screen overlays - Raster imagery draped over the terrain or pinned to the viewport for legends and controls.
- Camera and view control -
LookAtandCameraelements that steer where and how a feature is displayed. - KMZ packaging - A zipped container that bundles a KML document with its icons, images, and models.
- OGC standardization - A vendor-neutral specification that keeps KML interoperable beyond any single mapping product.
In API operations, KML shows up wherever a geospatial service needs a human-viewable, portable output format alongside machine-friendly formats like GeoJSON. Mapping and location APIs commonly offer KML as a content type so results drop straight into Google Earth or a GIS client, and government open-data portals lean on it for publishing boundaries, routes, and points of interest. As agents begin to consume spatial data, KML’s self-describing XML structure makes it straightforward to parse, summarize, and re-render without proprietary tooling.
