<P> Web Mercator, Google Web Mercator, Spherical Mercator, WGS 84 Web Mercator or WGS 84 / Pseudo-Mercator is a variant of the Mercator projection and is the de facto standard for Web mapping applications . It rose to prominence when Google Maps adopted it in 2005 . It is used by virtually all major online map providers, including Google Maps, MapBox, Bing Maps, OpenStreetMap, Mapquest, Esri, and many others . Its official EPSG identifier is EPSG: 3857, although others have been used historically . </P> <P> Web Mercator is a slight variant of the Mercator projection, one used primarily in Web - based mapping programs . It uses the same formulas as the standard Mercator as used for small - scale maps . However, the Web Mercator uses the spherical formulas at all scales whereas large - scale Mercator maps normally use the ellipsoidal form of the projection . The discrepancy is imperceptible at the global scale but causes maps of local areas to deviate slightly from true ellipsoidal Mercator maps at the same scale . This deviation becomes more pronounced further from the equator, and can reach as much as 40 km on the ground . </P>

What coordinate system is used by google maps