File extension

.geojson

GeoJSON geographic data

.geojson files are GeoJSON documents: a JSON-based format for encoding geographic features such as points, lines, and polygons together with their attributes.

Known meanings

Formats and reference material for .geojson

GeoJSON geographic data

JSON format for geographic features, geometries, and properties, standardized in RFC 7946

  • gis-formats data-format internet
  • IETF (Butler et al.)
Open link

Details

Format notes

GeoJSON

GeoJSON is a format for representing simple geographic features and their non-spatial attributes using JSON. A document is a single JSON object whose type member identifies it as a geometry, a Feature, or a FeatureCollection. The supported geometry types are Point, MultiPoint, LineString, MultiLineString, Polygon, MultiPolygon, and GeometryCollection. A Feature pairs one geometry with a free-form properties object, and a FeatureCollection holds a list of features.

Technical Notes

GeoJSON is plain UTF-8 text, so it can be read and edited with any text editor and handled by any JSON parser. Coordinates are arrays of numbers in longitude, latitude order, with an optional third element for elevation. The IETF standard, RFC 7946 (2016), fixes the coordinate reference system to WGS 84 and replaced the earlier 2008 community specification, which allowed other coordinate reference systems. Files commonly use the .geojson extension, but .json is also used. The registered media type is application/geo+json.

Adoption

GeoJSON is widely supported by web mapping libraries, GIS desktop software, spatial databases, and web APIs, and it is a common interchange format for small and medium datasets. Being text-based, it is verbose for large datasets and has no built-in spatial index, so formats such as GeoPackage or vector tiles are often used for large or performance-sensitive data.

Preservation And Security Notes

The format is open, human-readable, and fully specified, which makes it a suitable long-term format for vector data. Because geometry is limited to WGS 84 and attribute schemas are not declared, keep any needed metadata (such as source, date, and attribute meaning) alongside the file. Parsers should handle untrusted input defensively, as with any JSON, particularly deeply nested structures and very large coordinate arrays.

Further Reading

  • GeoJSON site: https://geojson.org/
  • RFC 7946, The GeoJSON Format: https://datatracker.ietf.org/doc/html/rfc7946