# projection

**Projections** are methods of transforming the coordinates of locations on a three-dimensional planet to a two-dimensional plane.

Mapbox uses the popular Web Mercator projection with the EPSG:3857 projected coordinate system as the default projection for maps and map tiles. Because Web Mercator is used by most web maps, you can often combine map tiles and layers from other platforms that use the same projection with your Mapbox maps.

Mapbox tools will transform accepted coordinate inputs for display using the Web Mercator projection. Mapbox tools accept coordinate inputs as follows:

- Mapbox Tiling Service and Mapbox SDKs for mobile and web accept GeoJSON that follows the GeoJSON standard for a geographic coordinate reference system equivalent to OGC:CRS84, using the WGS84 datum, decimal degrees, and longitude and latitude units (in that order).
- The Mapbox Uploads API accepts data inputs in a variety of formats and projections.

Later versions of the EPSG:4326 coordinate reference system order coordinates as `latitude,longitude`

, which is the reverse order of coordinates in OGC:CRS84. Most Mapbox upload tools require coordinates ordered as `longitude,latitude`

.

**Related resources:**