4326

4326 typically refers to EPSG:4326, the WGS 84 geographic coordinate system. It defines locations on the Earth’s surface using latitude and longitude expressed in decimal degrees, based on the WGS 84 geodetic datum. As a geographic coordinate system, EPSG:4326 uses no map projection; coordinates correspond to positions on the ellipsoid rather than on a specific plane.

In practice, coordinates in this system are given as latitude and longitude in decimal degrees. For example, a point in New York City is commonly represented as latitude 40.7128, longitude -74.0060. The valid ranges are -90 to 90 degrees for latitude and -180 to 180 degrees for longitude. EPSG:4326 is widely used because it aligns with GPS data and serves as a common interchange format for geospatial datasets.

Applications and usage: EPSG:4326 is the default or de facto standard in many geospatial workflows for data storage, sharing, and interoperability. Web mapping applications and geographic information systems frequently store or exchange data in this CRS before converting to a projected coordinate system for rendering or analysis.

Relation to other systems: Because it is a geographic rather than projected coordinate system, EPSG:4326 coordinates are typically transformed to projected CRSs (for example, Web Mercator, EPSG:3857) to perform distance measurements, area calculations, or to display data on planar maps. The datum underlying EPSG:4326 is WGS 84, which provides a globally consistent frame of reference, though small shifts can occur when transforming to other datums.

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