Best map projection for web maps
For a zoomable, tiled web map, use Web Mercator (EPSG:3857), a variant of the Mercator projection. It keeps local angles, so streets and buildings look right at every zoom level, and the whole world fits into a square that splits into tiles.
Best choice: Web Mercator (a Mercator variant)
Conformal, cylindrical
Tiled web maps such as Google Maps and OpenStreetMap use a Mercator variant called Web Mercator (EPSG:3857). It keeps local angles, so streets meet at the right angles at every zoom level.
Note: Zoomed out to the whole world, don't compare areas on this map. Add an equal-area map for those views.
- Area: distorted
- Shape: preserved
- Distances: distorted
- Angles and directions: preserved
- Continuity: preserved
Also good
No other projection in our catalogue meets this need as well.
What to avoid
It does not keep angles, so streets and buildings would look skewed.
See the problem on the map →A different goal or map shape? Change the answers in the finder →
Why web maps chose Mercator
A zoomable map has to work the same way at the scale of a continent and of a single street. A conformal projection keeps local angles, so a right-angled junction stays a right angle and north points up everywhere on the map.
Web Mercator clips the map at about 85° of latitude, so the whole world fits into a square that divides into ever smaller tiles. It computes coordinates as if the Earth were a sphere, which simplifies the maths at the cost of small scale errors.
The price of that choice
Zoomed out to the whole world, Web Mercator fails just like classic Mercator: it enlarges areas far from the equator. A web map is therefore a poor tool for comparing country sizes.
If your app shows data for the whole world, such as results by country, add a view in an equal-area projection like Equal Earth.
When the app needs raw data
Raster data and globe textures are often stored on a Plate Carrée grid, in which longitude and latitude map straight to x and y. It is a convenient storage format but a poor map to look at, because it stretches the polar regions horizontally.
Frequently asked questions
The tiled maps of Google Maps and OpenStreetMap use Web Mercator, a variant of the Mercator projection with the code EPSG:3857.
Almost. Web Mercator computes coordinates as if the Earth were a sphere, although it stores data in WGS 84, and it clips the map at about 85° of latitude. It looks like classic Mercator and shares its strengths and weaknesses.
Only at a small scale and with a correction for latitude. Web Mercator's scale grows toward the poles, so measuring on screen overstates the area of places far from the equator.
The best projection for other jobs
- Comparing country sizesEqual Earth
- Thematic and data mapsEqual Earth
- Wall maps and postersWinkel Tripel
- Flight routesGnomonic
- Navigation and compass coursesMercator
- Distances from one placeAzimuthal Equidistant
- The Arctic and AntarcticaAzimuthal Equidistant
- Oceans and currentsSpilhaus Projection
- Teaching geographyEqual Earth