What is GeoJSON? Complete Guide with Examples

What is GeoJSON?

GeoJSON is an open standard format designed for representing simple geographical features, along with their non-spatial attributes. Based on JavaScript Object Notation (JSON), it's become the de facto standard for web-based mapping applications and APIs.

Created in 2008 and standardized as RFC 7946 in 2016, GeoJSON provides a lightweight, human-readable way to encode geographic data structures including points, lines, polygons, and collections of these geometries.

Key Features

• Human-readable JSON format
• Widely supported by mapping libraries
• Lightweight and efficient
• Supports complex geometries and properties
• Web-friendly and API-compatible

GeoJSON Structure

Every GeoJSON object has a type property that indicates the type of geometry or feature:

Geometry Types

• Point: A single position
• LineString: An array of positions forming a line
• Polygon: An array of linear rings (closed LineStrings)
• MultiPoint: Multiple points
• MultiLineString: Multiple lines
• MultiPolygon: Multiple polygons
• GeometryCollection: Collection of geometry objects

Feature Objects

Features combine geometry with properties, allowing you to attach metadata to geographic shapes.

Examples

Simple Point

{
  "type": "Feature",
  "geometry": {
    "type": "Point",
    "coordinates": [-122.4194, 37.7749]
  },
  "properties": {
    "name": "San Francisco",
    "population": 883305
  }
}

Polygon Example

{
  "type": "Feature",
  "geometry": {
    "type": "Polygon",
    "coordinates": [[
      [-122.4, 37.8],
      [-122.4, 37.7],
      [-122.3, 37.7],
      [-122.3, 37.8],
      [-122.4, 37.8]
    ]]
  },
  "properties": {
    "name": "Sample Area"
  }
}

Common Use Cases