GeoJSON Format Guide

What is GeoJSON?

GeoJSON is an open standard format (RFC 7946) for encoding geographic data structures using JSON. It's the native format for most web mapping libraries and APIs.

Structure

A GeoJSON file contains a single object — typically a FeatureCollection containing an array of Feature objects. Each feature has a geometry (Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon, or GeometryCollection) and a properties object for attributes.

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "geometry": {
        "type": "Point",
        "coordinates": [-73.9857, 40.7484]
      },
      "properties": {
        "name": "Empire State Building"
      }
    }
  ]
}

Key Characteristics

• CRS: GeoJSON uses WGS 84 (EPSG:4326) exclusively. Coordinates are [longitude, latitude].
• Human-readable: Plain text JSON makes it easy to inspect and debug.
• Web-native: Directly consumable by Leaflet, Mapbox GL, OpenLayers, and D3.js.
• No file size limit: But large files (>50 MB) can be slow to parse in browsers.

Limitations

• No support for CRS other than WGS 84 — data is always reprojected on conversion.
• No built-in styling — styling is applied by the consuming application.
• Verbose format — larger file sizes compared to binary formats like GeoPackage or FlatGeobuf.

Converting GeoJSON

Upload your .geojson or .json file to ConvertGeoData. If your data isn't already in WGS 84, we'll handle the reprojection automatically during conversion.

Popular conversions: GeoJSON to Shapefile, GeoJSON to KML, GeoJSON to GeoPackage.