The spatialReference object is located at the top level of the web map JSON hierarchy. In addition to this, it is also available within the operationalLayer and basemap objects.

Many predefined spatial references have already been defined and are available for use. A spatial reference can be defined using a well-known ID (WKID) or well-known text (WKT). The default tolerance and resolution values for the associated coordinate system are used. It is required to have this property saved within the web map.


Property Details
latestWkid (Optional) Identifies the current wkid value associated with the same spatial reference. For example a WKID of '102100' (Web Mercator) has a latestWKid of '3857'.
wkid The well-known ID (WKID) of the coordinate system. Specify either WKID or the well-known text (WKT) of the coordinate system.
wkt The well-known text (WKT) of the coordinate system. Specify either WKT or WKID of the coordinate system.

Additional information

All operational layers in the map are drawn or requested in the spatial reference of the basemap layers.

The basemap defines the map spatial reference and tiling scheme. Each baseMapLayer must be in the same spatial reference and tiling scheme.

For a complete list of supported IDs and their corresponding definition strings, see:

Projected Coordinate Systems Listing

Geographic Coordinate Systems Listing

Vertical Coordinate Systems Listing

Additional information regarding how web maps work with geometry and spatial reference can be found on the Resource Center:

ArcGIS Server REST API Geometry object

Using spatial references

Working with Geometry Objects


  "spatialreference": {
    "wkid": 102100,
    "latestWkid": 3857

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