Mapbox.js is no longer in active development. To learn more about our newer mapping tools see Mapbox GL JS.


An object with methods for projecting geographical coordinates of the world onto a flat surface (and back). See Map projection.


Method Returns Description
project( <LatLng> latlng ) Point Projects geographical coordinates into a 2D point.
unproject( <Point> point ) LatLng The inverse of project. Projects a 2D point into geographical location.

Defined Projections

Leaflet comes with a set of already defined projections out of the box:

Projection Description
L.Projection.SphericalMercator Spherical Mercator projection — the most common projection for online maps, used by almost all free and commercial tile providers. Assumes that Earth is a sphere. Used by the EPSG:3857 CRS.
L.Projection.Mercator Elliptical Mercator projection — more complex than Spherical Mercator. Takes into account that Earth is a geoid, not a perfect sphere. Used by the EPSG:3395 CRS.
L.Projection.LonLat Equirectangular, or Plate Carree projection — the most simple projection, mostly used by GIS enthusiasts. Directly maps x as longitude, and y as latitude. Also suitable for flat worlds, e.g. game maps. Used by the EPSG:3395 and Simple CRS.