You're all set!

To start developing, please head over to our developer documentation.

Activate the Google Maps JavaScript API

To get you started we'll guide you through the Google Developers Console to do a few things first:

  1. Create or choose a project
  2. Activate the Google Maps JavaScript API and related services
  3. Create appropriate keys
Continue

Custom map projections

Read the documentation or view this example full screen.

// This example defines an image map type using the Gall-Peters
// projection.
// https://en.wikipedia.org/wiki/Gall%E2%80%93Peters_projection

function initMap() {
  // Create a map. Use the Gall-Peters map type.
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 0,
    center: {lat: 0, lng: 0},
    mapTypeControl: false
  });

  initGallPeters();
  map.mapTypes.set('gallPeters', gallPetersMapType);
  map.setMapTypeId('gallPeters');

  // Show the lat and lng under the mouse cursor.
  var coordsDiv = document.getElementById('coords');
  map.controls[google.maps.ControlPosition.TOP_CENTER].push(coordsDiv);
  map.addListener('mousemove', function(event) {
    coordsDiv.textContent =
        'lat: ' + Math.round(event.latLng.lat()) + ', ' +
        'lng: ' + Math.round(event.latLng.lng());
  });

  // Add some markers to the map.
  map.data.setStyle(function(feature) {
    return {
      title: feature.getProperty('name'),
      optimized: false
    };
  });
  map.data.addGeoJson(cities);
}

var gallPetersMapType;
function initGallPeters() {
  var GALL_PETERS_RANGE_X = 800;
  var GALL_PETERS_RANGE_Y = 512;

  // Fetch Gall-Peters tiles stored locally on our server.
  gallPetersMapType = new google.maps.ImageMapType({
    getTileUrl: function(coord, zoom) {
      var scale = 1 << zoom;

      // Wrap tiles horizontally.
      var x = ((coord.x % scale) + scale) % scale;

      // Don't wrap tiles vertically.
      var y = coord.y;
      if (y < 0 || y >= scale) return null;

      return 'https://developers.google.com/maps/documentation/' +
             'javascript/examples/full/images/gall-peters_' + zoom +
             '_' + x + '_' + y + '.png';
    },
    tileSize: new google.maps.Size(GALL_PETERS_RANGE_X, GALL_PETERS_RANGE_Y),
    isPng: true,
    minZoom: 0,
    maxZoom: 1,
    name: 'Gall-Peters'
  });

  // Describe the Gall-Peters projection used by these tiles.
  gallPetersMapType.projection = {
    fromLatLngToPoint: function(latLng) {
      var latRadians = latLng.lat() * Math.PI / 180;
      return new google.maps.Point(
          GALL_PETERS_RANGE_X * (0.5 + latLng.lng() / 360),
          GALL_PETERS_RANGE_Y * (0.5 - 0.5 * Math.sin(latRadians)));
    },
    fromPointToLatLng: function(point, noWrap) {
      var x = point.x / GALL_PETERS_RANGE_X;
      var y = Math.max(0, Math.min(1, point.y / GALL_PETERS_RANGE_Y));

      return new google.maps.LatLng(
          Math.asin(1 - 2 * y) * 180 / Math.PI,
          -180 + 360 * x,
          noWrap);
    }
  };
}

// GeoJSON, describing the locations and names of some cities.
var cities = {
  type: 'FeatureCollection',
  features: [{
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [-87.650, 41.850]},
    properties: {name: 'Chicago'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [-149.900, 61.218]},
    properties: {name: 'Anchorage'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [-99.127, 19.427]},
    properties: {name: 'Mexico City'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [-0.126, 51.500]},
    properties: {name: 'London'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [28.045, -26.201]},
    properties: {name: 'Johannesburg'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [15.322, -4.325]},
    properties: {name: 'Kinshasa'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [151.207, -33.867]},
    properties: {name: 'Sydney'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [0, 0]},
    properties: {name: '0°N 0°E'}
  }]
};
<div id="map"></div>
<div id="coords"></div>
html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}
#map {
  height: 100%;
}
#coords {
  background-color: black;
  color: white;
  padding: 5px;
}
<!-- Replace the value of the key parameter with your own API key. -->
<script async defer src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&callback=initMap"></script>
JavaScript
// This example defines an image map type using the Gall-Peters
// projection.
// https://en.wikipedia.org/wiki/Gall%E2%80%93Peters_projection

function initMap() {
  // Create a map. Use the Gall-Peters map type.
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 0,
    center: {lat: 0, lng: 0},
    mapTypeControl: false
  });

  initGallPeters();
  map.mapTypes.set('gallPeters', gallPetersMapType);
  map.setMapTypeId('gallPeters');

  // Show the lat and lng under the mouse cursor.
  var coordsDiv = document.getElementById('coords');
  map.controls[google.maps.ControlPosition.TOP_CENTER].push(coordsDiv);
  map.addListener('mousemove', function(event) {
    coordsDiv.textContent =
        'lat: ' + Math.round(event.latLng.lat()) + ', ' +
        'lng: ' + Math.round(event.latLng.lng());
  });

  // Add some markers to the map.
  map.data.setStyle(function(feature) {
    return {
      title: feature.getProperty('name'),
      optimized: false
    };
  });
  map.data.addGeoJson(cities);
}

var gallPetersMapType;
function initGallPeters() {
  var GALL_PETERS_RANGE_X = 800;
  var GALL_PETERS_RANGE_Y = 512;

  // Fetch Gall-Peters tiles stored locally on our server.
  gallPetersMapType = new google.maps.ImageMapType({
    getTileUrl: function(coord, zoom) {
      var scale = 1 << zoom;

      // Wrap tiles horizontally.
      var x = ((coord.x % scale) + scale) % scale;

      // Don't wrap tiles vertically.
      var y = coord.y;
      if (y < 0 || y >= scale) return null;

      return 'https://developers.google.com/maps/documentation/' +
             'javascript/examples/full/images/gall-peters_' + zoom +
             '_' + x + '_' + y + '.png';
    },
    tileSize: new google.maps.Size(GALL_PETERS_RANGE_X, GALL_PETERS_RANGE_Y),
    isPng: true,
    minZoom: 0,
    maxZoom: 1,
    name: 'Gall-Peters'
  });

  // Describe the Gall-Peters projection used by these tiles.
  gallPetersMapType.projection = {
    fromLatLngToPoint: function(latLng) {
      var latRadians = latLng.lat() * Math.PI / 180;
      return new google.maps.Point(
          GALL_PETERS_RANGE_X * (0.5 + latLng.lng() / 360),
          GALL_PETERS_RANGE_Y * (0.5 - 0.5 * Math.sin(latRadians)));
    },
    fromPointToLatLng: function(point, noWrap) {
      var x = point.x / GALL_PETERS_RANGE_X;
      var y = Math.max(0, Math.min(1, point.y / GALL_PETERS_RANGE_Y));

      return new google.maps.LatLng(
          Math.asin(1 - 2 * y) * 180 / Math.PI,
          -180 + 360 * x,
          noWrap);
    }
  };
}

// GeoJSON, describing the locations and names of some cities.
var cities = {
  type: 'FeatureCollection',
  features: [{
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [-87.650, 41.850]},
    properties: {name: 'Chicago'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [-149.900, 61.218]},
    properties: {name: 'Anchorage'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [-99.127, 19.427]},
    properties: {name: 'Mexico City'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [-0.126, 51.500]},
    properties: {name: 'London'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [28.045, -26.201]},
    properties: {name: 'Johannesburg'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [15.322, -4.325]},
    properties: {name: 'Kinshasa'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [151.207, -33.867]},
    properties: {name: 'Sydney'}
  }, {
    type: 'Feature',
    geometry: {type: 'Point', coordinates: [0, 0]},
    properties: {name: '0°N 0°E'}
  }]
};
JavaScript + HTML
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Custom map projections</title>
    <style>
      html, body {
        height: 100%;
        margin: 0;
        padding: 0;
      }
      #map {
        height: 100%;
      }
      #coords {
        background-color: black;
        color: white;
        padding: 5px;
      }
    </style>
  </head>
  <body>
    <div id="map"></div>
    <div id="coords"></div>
    <script>
      // This example defines an image map type using the Gall-Peters
      // projection.
      // https://en.wikipedia.org/wiki/Gall%E2%80%93Peters_projection

      function initMap() {
        // Create a map. Use the Gall-Peters map type.
        var map = new google.maps.Map(document.getElementById('map'), {
          zoom: 0,
          center: {lat: 0, lng: 0},
          mapTypeControl: false
        });

        initGallPeters();
        map.mapTypes.set('gallPeters', gallPetersMapType);
        map.setMapTypeId('gallPeters');

        // Show the lat and lng under the mouse cursor.
        var coordsDiv = document.getElementById('coords');
        map.controls[google.maps.ControlPosition.TOP_CENTER].push(coordsDiv);
        map.addListener('mousemove', function(event) {
          coordsDiv.textContent =
              'lat: ' + Math.round(event.latLng.lat()) + ', ' +
              'lng: ' + Math.round(event.latLng.lng());
        });

        // Add some markers to the map.
        map.data.setStyle(function(feature) {
          return {
            title: feature.getProperty('name'),
            optimized: false
          };
        });
        map.data.addGeoJson(cities);
      }

      var gallPetersMapType;
      function initGallPeters() {
        var GALL_PETERS_RANGE_X = 800;
        var GALL_PETERS_RANGE_Y = 512;

        // Fetch Gall-Peters tiles stored locally on our server.
        gallPetersMapType = new google.maps.ImageMapType({
          getTileUrl: function(coord, zoom) {
            var scale = 1 << zoom;

            // Wrap tiles horizontally.
            var x = ((coord.x % scale) + scale) % scale;

            // Don't wrap tiles vertically.
            var y = coord.y;
            if (y < 0 || y >= scale) return null;

            return 'https://developers.google.com/maps/documentation/' +
                   'javascript/examples/full/images/gall-peters_' + zoom +
                   '_' + x + '_' + y + '.png';
          },
          tileSize: new google.maps.Size(GALL_PETERS_RANGE_X, GALL_PETERS_RANGE_Y),
          isPng: true,
          minZoom: 0,
          maxZoom: 1,
          name: 'Gall-Peters'
        });

        // Describe the Gall-Peters projection used by these tiles.
        gallPetersMapType.projection = {
          fromLatLngToPoint: function(latLng) {
            var latRadians = latLng.lat() * Math.PI / 180;
            return new google.maps.Point(
                GALL_PETERS_RANGE_X * (0.5 + latLng.lng() / 360),
                GALL_PETERS_RANGE_Y * (0.5 - 0.5 * Math.sin(latRadians)));
          },
          fromPointToLatLng: function(point, noWrap) {
            var x = point.x / GALL_PETERS_RANGE_X;
            var y = Math.max(0, Math.min(1, point.y / GALL_PETERS_RANGE_Y));

            return new google.maps.LatLng(
                Math.asin(1 - 2 * y) * 180 / Math.PI,
                -180 + 360 * x,
                noWrap);
          }
        };
      }

      // GeoJSON, describing the locations and names of some cities.
      var cities = {
        type: 'FeatureCollection',
        features: [{
          type: 'Feature',
          geometry: {type: 'Point', coordinates: [-87.650, 41.850]},
          properties: {name: 'Chicago'}
        }, {
          type: 'Feature',
          geometry: {type: 'Point', coordinates: [-149.900, 61.218]},
          properties: {name: 'Anchorage'}
        }, {
          type: 'Feature',
          geometry: {type: 'Point', coordinates: [-99.127, 19.427]},
          properties: {name: 'Mexico City'}
        }, {
          type: 'Feature',
          geometry: {type: 'Point', coordinates: [-0.126, 51.500]},
          properties: {name: 'London'}
        }, {
          type: 'Feature',
          geometry: {type: 'Point', coordinates: [28.045, -26.201]},
          properties: {name: 'Johannesburg'}
        }, {
          type: 'Feature',
          geometry: {type: 'Point', coordinates: [15.322, -4.325]},
          properties: {name: 'Kinshasa'}
        }, {
          type: 'Feature',
          geometry: {type: 'Point', coordinates: [151.207, -33.867]},
          properties: {name: 'Sydney'}
        }, {
          type: 'Feature',
          geometry: {type: 'Point', coordinates: [0, 0]},
          properties: {name: '0°N 0°E'}
        }]
      };
    </script>
    <script async defer src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap"></script>
  </body>
</html>

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