EPSG Codes

Overview EPSG codes are numeric identifiers from the EPSG Geodetic Parameter Dataset, originally established by the European Petroleum Survey Group and now maintained by the International Association of Oil and Gas Producers (IOGP). Each code uniquely identifies a coordinate reference system, datumDatumA geodetic datum is a mathematical model that defines the size, shape, and orientation of the Earth, serving as the r..., ellipsoid, projection, or unit of measurement, providing a compact and unambiguous way to specify how geographic coordinates relate to real-world positions.

Several EPSG codes are fundamental to GISGISGeographic Information Systems (GIS) enable users to analyze and visualize spatial data to uncover patterns, relation... practice. EPSG:4326 designates WGS 84WGS 84WGS 84 (World Geodetic System 1984) is the global geodetic reference system used by GPS and most modern mapping appli... geographic coordinates (latitude/longitude). EPSG:3857 identifies Web Mercator, used by most web mapping platforms. EPSG:4269 refers to NAD 83NAD 83NAD 83 (North American Datum of 1983) is the horizontal geodetic datum used for surveying, mapping, and navigation ac... geographic coordinates. EPSG:32601 through EPSG:32660 cover UTM zones 1N through 60N on WGS 84. The registry contains over 6,000 entries covering coordinate systemsCoordinate SystemsCoordinate systems standardize the description of geographic locations using latitude, longitude, and other spatial d... used worldwide, from global references to country-specific and regional projections.

EPSG codes appear throughout geospatial workflows. GISGISGeographic Information Systems (GIS) enable users to analyze and visualize spatial data to uncover patterns, relation... software uses them to define layer coordinate systemsCoordinate SystemsCoordinate systems standardize the description of geographic locations using latitude, longitude, and other spatial d... and perform on-the-fly reprojection. Spatial databasesSpatial DatabasesSpatial databases are specialized systems designed to store, query, and manage data related to objects in geographic ... like PostGISPostGISPostGIS is an open-source extension for PostgreSQL databases that introduces support for geographic objects, allowing... store SRID (Spatial ReferenceSpatial ReferenceA spatial reference defines how the coordinates in a geospatial dataset correspond to real-world locations on Earth. ... Identifier) values that correspond to EPSG codes. Web mapping standards such as WMS and WFS use EPSG codes in service requests to specify the desired coordinate system. Geospatial file formats including GeoTIFFGeoTIFFGeoTIFF is a public domain metadata standard that embeds georeferencing information within TIFF image files, enabling..., GeoJSONGeoJSONGeoJSON is an open standard format for encoding geographic data structures using JavaScript Object Notation (JSON). I..., and GeoPackage embed EPSG codes in their metadata to declare the spatial reference of stored data.

The EPSG registry is freely accessible online and through APIs, providing detailed parameter definitions for each code including the datumDatumA geodetic datum is a mathematical model that defines the size, shape, and orientation of the Earth, serving as the r..., ellipsoid, projection method, and transformation parameters. GISGISGeographic Information Systems (GIS) enable users to analyze and visualize spatial data to uncover patterns, relation... libraries like PROJPROJPROJ is the foundational open-source library for cartographic projections and coordinate transformations used across ..., GDALGDALGDAL (Geospatial Data Abstraction Library) is an open-source translator library for raster and vector geospatial data..., and pyprojPyProjPyProj is a Python interface to the PROJ library for cartographic projections and coordinate transformations. It enab... include built-in copies of the EPSG database for offline coordinate transformations. The registry is updated regularly to add new entries and refine existing definitions.