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{{Infobox file format
| name                   = GeoJSON
| logo                   = 
| icon                   = 
| iconcaption            = 
| screenshot             = 
| caption                = 
|_noextcode              = on
| extensions             = <code>.json</code>, <code>.geojson</code>
| mime                   = application/vnd.geo+json
| type code              = 
| uniform type           = 
| conforms to            = 
| magic                  = 
| owner                  = 
| released               = <!-- {{Start date and age|YYYY|mm|dd|df=yes/no}} -->
| latest release version = 
| latest release date    = <!-- {{Start date and age|YYYY|mm|dd|df=yes/no}} -->
| genre                  = [[GIS file formats|GIS file format]]
| container for          = 
| contained by           = 
| extended from          = [[JSON]]
| extended to            = 
| standard               = 
| free                   = yes
| url                    = {{URL|http://geojson.org/}}
}}

'''GeoJSON'''<ref>[http://geojson.org/geojson-spec.html The GeoJSON Format Specification]</ref> is an [[open standard]] format designed for representing [[Simple Features|simple geographical features]], along with their non-spatial attributes, based on [[JSON|JavaScript Object Notation]].<ref name="RichardsonAmundsen2013">{{cite book|author1=Leonard Richardson|author2=Mike Amundsen|author3=Sam Ruby|title=RESTful Web APIs|url=http://books.google.com/books?id=wWnGAAAAQBAJ&pg=PA228|date=12 September 2013|publisher="O'Reilly Media, Inc."|isbn=978-1-4493-5974-4|page=228|quote=Geojson: A Trobled Type     ... a standard based on JSON, designed for representing geographic features like points on a map. ... There's another problem with GeoJSON: Iit has no registered media type. A GeoJSON document is served as application/json, just like any other JSON document. How is a client supposed to distinguish between geoJSON and plain old JSON? }}</ref><ref name="Westra2015">{{cite book|author=Erik Westra|title=Python Geospatial Analysis Essentials|url=http://books.google.com/books?id=bJ_5CQAAQBAJ&pg=PA27|date=23 June 2015|publisher=Packt Publishing Ltd|isbn=978-1-78355-389-1|page=27|quote=GeoJSON ... is an open standard used to represent geospatial data structures as JavaScript Object Notation (JSON) objects.}}</ref>

The features include points (therefore addresses and locations), [[Polygonal chain|line strings]] (therefore streets, highways and boundaries), [[polygon]]s (countries, provinces, tracts of land), and multi-part collections of these types. GeoJSON features need not represent entities of the physical world only; mobile routing and navigation apps, for example, might describe their service coverage using GeoJSON.<ref>[https://developer.apple.com/library/ios/documentation/userexperience/conceptual/LocationAwarenessPG/ProvidingDirections/ProvidingDirections.html iOS Location and Maps Programming Guide]</ref>

The GeoJSON format differs from other [[Geographic information system|GIS]] standards in that it was written and is maintained not by a formal standards organization, but by an Internet working group of developers.<ref>[http://lists.geojson.org/listinfo.cgi/geojson-geojson.org The GeoJSON Discussion List]</ref>

A notable offspring of GeoJSON is [[#TopoJSON|TopoJSON]], an extension of GeoJSON that encodes [[geospatial topology]] and that typically provides smaller file sizes.

==History==

The GeoJSON format working group and discussion were begun in March 2007<ref>[http://lists.geojson.org/pipermail/geojson-geojson.org/2007-March/thread.html March 2007 Archives by thread]</ref> and the format specification was finalized in June 2008.

==Example==
<syntaxhighlight lang="JavaScript">
{ "type": "FeatureCollection",
    "features": [
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [102.0, 0.5]},
        "properties": {"prop0": "value0"}
        },
      { "type": "Feature",
        "geometry": {
          "type": "LineString",
          "coordinates": [
            [102.0, 0.0], [103.0, 1.0], [104.0, 0.0], [105.0, 1.0]
            ]
          },
        "properties": {
          "prop0": "value0",
          "prop1": 0.0
          }
        },
      { "type": "Feature",
         "geometry": {
           "type": "Polygon",
           "coordinates": [
             [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0],
               [100.0, 1.0], [100.0, 0.0] ]
             ]
         },
         "properties": {
           "prop0": "value0",
           "prop1": {"this": "that"}
           }
         }
       ]
     }
</syntaxhighlight>

===Geometries===

{| class="wikitable"
|+Geometry primitives
|-
! Type
!colspan="2"| Examples
|-
| [[Point (geometry)|Point]]
| [[File:SFA Point.svg]]
| <syntaxhighlight lang="JavaScript">{ "type": "Point", 
    "coordinates": [30, 10]
}</syntaxhighlight>
|-
| [[Line segment|LineString]]
| [[File:SFA LineString.svg]]
| <syntaxhighlight lang="JavaScript">{ "type": "LineString", 
    "coordinates": [
        [30, 10], [10, 30], [40, 40]
    ]
}</syntaxhighlight>
|-
|rowspan="2"| [[Polygon]]
| [[File:SFA Polygon.svg]]
| <syntaxhighlight lang="JavaScript">{ "type": "Polygon", 
    "coordinates": [
        [[30, 10], [40, 40], [20, 40], [10, 20], [30, 10]]
    ]
}</syntaxhighlight>
|-
| [[File:SFA Polygon with hole.svg]]
| <syntaxhighlight lang="JavaScript">{ "type": "Polygon", 
    "coordinates": [
        [[35, 10], [45, 45], [15, 40], [10, 20], [35, 10]], 
        [[20, 30], [35, 35], [30, 20], [20, 30]]
    ]
}</syntaxhighlight>
|}

{| class="wikitable"
|+Multipart geometries
|-
! Type
!colspan="2"| Examples
|-
|[[Point (geometry)|MultiPoint]]
| [[File:SFA MultiPoint.svg]]
| <syntaxhighlight lang="JavaScript">{ "type": "MultiPoint", 
    "coordinates": [
        [10, 40], [40, 30], [20, 20], [30, 10]
    ]
}</syntaxhighlight>
|-
| [[Line segment|MultiLineString]]
| [[File:SFA MultiLineString.svg]]
| <syntaxhighlight lang="JavaScript">{ "type": "MultiLineString", 
    "coordinates": [
        [[10, 10], [20, 20], [10, 40]], 
        [[40, 40], [30, 30], [40, 20], [30, 10]]
    ]
}</syntaxhighlight>
|-
|rowspan="2"| [[Polygon|MultiPolygon]]
| [[File:SFA MultiPolygon.svg]]
| <syntaxhighlight lang="JavaScript">{ "type": "MultiPolygon", 
    "coordinates": [
        [
            [[30, 20], [45, 40], [10, 40], [30, 20]]
        ], 
        [
            [[15, 5], [40, 10], [10, 20], [5, 10], [15, 5]]
        ]
    ]
}</syntaxhighlight>
|-
| [[File:SFA MultiPolygon with hole.svg]]
| <syntaxhighlight lang="JavaScript">{ "type": "MultiPolygon", 
    "coordinates": [
        [
            [[40, 40], [20, 45], [45, 30], [40, 40]]
        ], 
        [
            [[20, 35], [10, 30], [10, 10], [30, 5], [45, 20], [20, 35]], 
            [[30, 20], [20, 15], [20, 25], [30, 20]]
        ]
    ]
}</syntaxhighlight>
|}

==Supported software==
GeoJSON is supported by numerous mapping and [[GIS]] software packages, including [[OpenLayers]],<ref>http://openlayers.org/dev/examples/vector-formats.html</ref> [[Leafletjs|Leaflet]], [[MapServer]],<ref>http://mapserver.org/output/template_output.html</ref> [http://www.geoforge.org Geoforge] software,<ref>http://leafletjs.com/reference.html#geojson</ref> [[GeoServer]],<ref>http://svn.codehaus.org/geoserver/tags/2.0.0-alpha1/geoserver/release/README.txt</ref> [[Django (Web framework)|GeoDjango]],<ref>http://geodjango.org</ref> PointPlot, <ref>http://www.ndm.io</ref> [[GDAL]],<ref>http://gdal.org/ogr/drv_geojson.html</ref> [[Safe Software]] [[Feature Manipulation Engine|FME]],<ref>http://www.safe.com/reader_writerPDF/geojson.pdf</ref> and [[CartoDB]].<ref>http://developers.cartodb.com/documentation/cartodb-js.html</ref> It is also possible to use GeoJSON with [[PostGIS]]<ref>http://pugs.postgresql.org/files/Introduction_to_PostGIS_v1.0.pdf</ref> and [[Mapnik]],<ref>http://svn.mapnik.org/tags/release-0.6.0/docs/api_docs/python/mapnik-module.html</ref> both of which handle the format via the GDAL OGR conversion library. [[Bing Maps]], [[Yahoo!]] and [[Google]] also support GeoJSON in their API services.

The Google Maps Javascript API v3 directly supports the integration of GeoJSON data layers <ref>https://developers.google.com/maps/documentation/javascript/examples/layer-data-simple</ref> as of March 19, 2014.<ref>http://googledevelopers.blogspot.com/2014/03/maps-made-easier-geojson-in-javascript.html</ref>

[[GitHub]] also supports GeoJSON rendering<ref>https://github.com/blog/1528-there-s-a-map-for-that</ref> and [[Potrace]] GeoJSON export.

== TopoJSON ==
TopoJSON is an extension of GeoJSON that encodes [[Geospatial topology|topology]]. Rather than representing geometries discretely, geometries in TopoJSON files are stitched together from shared line segments called ''arcs''.<ref>https://github.com/topojson/topojson-specification</ref> ''Arcs'' are sequences of points, while line strings and polygons are defined as sequences of arcs. Each arc is defined only once, but can be referenced several times by different shapes, thus reducing redundancy and decreasing the file size.<ref>https://github.com/mbostock/topojson/wiki</ref> In addition, TopoJSON facilitates applications that use topology, such as topology-preserving shape simplification, automatic map coloring, and [[cartogram]]s.

A [https://github.com/mbostock/topojson reference implementation] of the [https://github.com/topojson/topojson-specification/blob/master/README.md TopoJSON specification] is available as a command-line tool to encode TopoJSON from GeoJSON (or ESRI Shapefiles) and a [[client side]] [[JavaScript library]] to decode TopoJSON back to GeoJSON again. TopoJSON is also supported by the popular OGR tool as of version 1.11<ref>[http://trac.osgeo.org/gdal/wiki/Release/1.11.0-News GDAL/OGR 1.11.0 Release Notes]</ref> and PostGIS as of version 2.1.0.<ref>[http://postgis.net/docs/AsTopoJSON.html PostGIS AsTopoJSON]</ref>

=== TopoJSON Schema ===
Given a [[GIS]] shape near [[coordinates]] [[latitude]] 0° en [[longitude]] 0° a simple but valid and complete topojson file containing all metadata, ''Polygon'', ''LineString'', ''Point'' elements, ''arcs'' and ''properties'' is defined as follows:
[[File:Topojson shapes-en.svg|thumb|Topojson shapes|400px]]
<syntaxhighlight lang="JavaScript">
{
  "type":"Topology",
  "transform":{
    "scale": [1,1],
    "translate": [0,0]
  },
  "objects":{ 
    "two-squares":{
      "type": "GeometryCollection",
      "geometries":[
        {"type": "Polygon", "arcs":[[0,1]],"properties": {"name": "Left_Polygon" }},
        {"type": "Polygon", "arcs":[[2,-1]],"properties": {"name": "Right_Polygon" }}
      ]
    },
    "one-line": {
      "type":"GeometryCollection",
      "geometries":[
        {"type": "LineString", "arcs": [3],"properties":{"name":"Under_LineString"}}
      ]
    },
    "two-places":{
      "type":"GeometryCollection",
      "geometries":[
        {"type":"Point","coordinates":[0,0],"properties":{"name":"Origine_Point"}},
        {"type":"Point","coordinates":[0,-1],"properties":{"name":"Under_Point"}}
      ]
    }
  },
  "arcs": [
    [[1,2],[0,-2]],
    [[1,0],[-1,0],[0,2],[1,0]],
    [[1,2],[1,0],[0,-2],[-1,0]],
    [[0,-1],[2,0]]
  ]
}
</syntaxhighlight>

== References ==
<references/>

== Sources ==
* http://geojson.org/
* http://geojson.org/geojson-spec.html
* {{cite web | url=http://www.directionsmag.com/article.php?article_id=2550 | title=Emerging Technology: AJAX and GeoJSON | date=18 September 2007 | first=Christopher | last=Andrews }}
* {{cite web | url=http://www.geowebguru.com/articles/97-technical-overview-geojson | title=Geoweb Guru: Technical Overview: GeoJSON | date=16 February 2009}}
* {{cite web | url=http://googlegeodevelopers.blogspot.com/2009/05/build-on-top-of-your-public-latitude.html | title=Google Geo Developers Blog: Build on top of your public Latitude location with GeoJSON & KML | date=4 May 2009 | first=Chris | last=Lambert}}
* https://github.com/mbostock/topojson
* https://github.com/topojson/topojson-specification