Should Google Maps Use a 3D Globe? Evolution of web maps
How web maps moved from a flat Web Mercator view to a globe when zoomed out, and why Mercator still works well at street level.
The era of Web Mercator: why the web chose a flat map
Google Maps launched on 8 February 2005, first for desktop computers. Its maps use a variant of the Mercator projection called Web Mercator. Why use a projection that distorts country sizes so heavily at the scale of the whole world?
The reason is practical. The Mercator projection is conformal: in small areas it keeps angles and shapes. When you zoom in to street level in any city, right-angled intersections still look square, and building outlines are not squeezed in one direction. A Mercator map can also be cut easily into square tiles. The Google Maps Platform documentation describes the basic tile as a square of 256 by 256 pixels and cuts the world image off at about 85° north and south so that it forms a square.
Which projection inflates areas near the poles the most?
Google switches to a globe (2018)
The price of Web Mercator was keeping illusions about country sizes alive. Looking at a screen, it is easy to believe that Greenland is as big as Africa. In August 2018 Google changed Google Maps on desktop: when you zoom all the way out, the flat map turns into a three-dimensional globe. At first this applied only to the desktop version, not to the mobile apps.
Thanks to this change:
- Country proportions stopped misleading: on the globe Greenland does not look larger than Africa, which is roughly 14 times bigger.
- Routes look more intuitive: a globe shows the curved surface of the Earth. A great-circle route remains an arc, and its appearance on screen depends on the viewing direction.
Two scales, two tools
A globe when zoomed out and Web Mercator when zoomed in combine the strengths of both approaches. At street level a conformal map is convenient for navigation, while at world scale a globe does not misrepresent proportions. Keep in mind, though, that a globe view on a flat screen is an orthographic projection: it shows at most one hemisphere, and areas near the edge are squeezed.
Want to compare both views? Try our interactive map and the orthographic projection in the catalog of projections.