The service provides basic conversion of mapping data from the shapefile projection format -- .prj files -- to the encoding standard of the European Petroleum Survey Group (EPSG). The provider offers an interactive form to return EPSG codes matching a search term entered in a form or by parsing an uploaded .prj shapefile, and the same functions are available via API.
API methods support submitting search terms, either free-text keywords or contents of a .prj shapefile, as URL parameters. In keyword mode, the API returns any matching ESPG codes. In WKT mode, the system parses the shapefile data and returns any missing code. Either way, the return data includes a URL to access the EPSG code description page for any matching code.