EPSG:CODE

Coordinate Transformations with Proj4js

Proj4js is a JavaScript library for performing coordinate transformations. It works in both browsers and Node.js.

Installation

Shell 
npm install proj4

Register a CRS Definition

JavaScript 
import proj4 from 'proj4';

// Register the CRS
proj4.defs("EPSG:5255",
  "+proj=tmerc +lat_0=0 +lon_0=33 +k=1 +x_0=500000 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs +type=crs"
);

Search for any EPSG code on the home page and copy the definition from the Proj4js tab.

Transform Coordinates

JavaScript 
// Transform from WGS84 to EPSG:5255
const result = proj4("EPSG:4326", "EPSG:5255", [33.0, 39.0]);
console.log(result); // [500000.00, 4317352.47]

// Inverse transform
const wgs84 = proj4("EPSG:5255", "EPSG:4326", [500000, 4317352]);
console.log(wgs84); // [33.0, 38.99...]

Usage with Leaflet

JavaScript 
import proj4 from 'proj4';
import 'proj4leaflet';

proj4.defs("EPSG:5255",
  "+proj=tmerc +lat_0=0 +lon_0=33 +k=1 +x_0=500000 +y_0=0 +ellps=GRS80 +units=m +no_defs"
);

const crs = new L.Proj.CRS('EPSG:5255',
  proj4.defs('EPSG:5255'), {
    origin: [0, 0],
    resolutions: [8192, 4096, 2048, 1024, 512, 256, 128, 64, 32, 16, 8, 4, 2, 1]
  }
);

const map = L.map('map', { crs: crs });

Usage with OpenLayers

JavaScript 
import proj4 from 'proj4';
import { register } from 'ol/proj/proj4';

proj4.defs("EPSG:5255",
  "+proj=tmerc +lat_0=0 +lon_0=33 +k=1 +x_0=500000 +y_0=0 +ellps=GRS80 +units=m +no_defs"
);
register(proj4);

// You can now use "EPSG:5255" in OpenLayers

Notes