GeoJSON
Also known as: .geojson file, geographic JSON, GeoJSON map data
GeoJSON is a JSON-based format for representing geographic features — points, lines, and polygons — along with their properties. It is the common, web-friendly way to store and exchange map data in browsers and mapping tools.
- JSON-based format for geographic features
- Stores points, lines, polygons, and properties
- Web-native; converts to/from KML and shapefiles
How GeoJSON works
GeoJSON is just JSON with an agreed structure for geography: features carry a geometry (a Point, LineString, or Polygon defined by coordinates) plus a properties object for attributes like name or category.
Because it is plain text JSON, it works naturally in web maps and JavaScript, and you can open and read it in any text editor. Coordinates are longitude, latitude in the WGS 84 reference system.
GeoJSON vs KML and shapefiles
GeoJSON is the lightweight, web-native choice, while KML is XML-based and tied to Google Earth, and shapefiles are an older GIS standard. Many tools convert freely among them.
Files grow with the number and detail of features; a dense polygon dataset can get large. For most web mapping, GeoJSON’s readability and JSON tooling make it the default.