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

Encoding methods

Read the documentation or view this example full screen.

// This example requires the Geometry library. Include the libraries=geometry
// parameter when you first load the API. For example:
// <script src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&libraries=geometry">

function initMap() {
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 14,
    center: {lat: 34.366, lng: -89.519}
  });
  var poly = new google.maps.Polyline({
    strokeColor: '#000000',
    strokeOpacity: 1,
    strokeWeight: 3,
    map: map
  });

  // Add a listener for the click event
  google.maps.event.addListener(map, 'click', function(event) {
    addLatLngToPoly(event.latLng, poly);
  });
}

/**
 * Handles click events on a map, and adds a new point to the Polyline.
 * Updates the encoding text area with the path's encoded values.
 */
function addLatLngToPoly(latLng, poly) {
  var path = poly.getPath();
  // Because path is an MVCArray, we can simply append a new coordinate
  // and it will automatically appear
  path.push(latLng);

  // Update the text field to display the polyline encodings
  var encodeString = google.maps.geometry.encoding.encodePath(path);
  if (encodeString) {
    document.getElementById('encoded-polyline').value = encodeString;
  }
}
<div id="map"></div>
<div id="right-panel">
  <div>Encoding:</div>
  <textarea id="encoded-polyline"></textarea>
</div>
#right-panel {
  font-family: 'Roboto','sans-serif';
  line-height: 30px;
  padding-left: 10px;
}

#right-panel select, #right-panel input {
  font-size: 15px;
}

#right-panel select {
  width: 100%;
}

#right-panel i {
  font-size: 12px;
}
html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}
#map {
  height: 100%;
  width: 50%;
  float: left;
}
#right-panel {
  width: 46%;
  float: left;
}
#encoded-polyline {
  height: 100px;
  width: 100%;
}
<!-- Replace the value of the key parameter with your own API key. -->
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&libraries=geometry&callback=initMap"
        async defer></script>

Try it yourself

Hover at top right of the code block to copy the code or open it in JSFiddle.

<!DOCTYPE html>
<html>
  <head>
    <title>Encoding methods</title>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no">
    <meta charset="utf-8">
    <style>
      #right-panel {
        font-family: 'Roboto','sans-serif';
        line-height: 30px;
        padding-left: 10px;
      }

      #right-panel select, #right-panel input {
        font-size: 15px;
      }

      #right-panel select {
        width: 100%;
      }

      #right-panel i {
        font-size: 12px;
      }
      html, body {
        height: 100%;
        margin: 0;
        padding: 0;
      }
      #map {
        height: 100%;
        width: 50%;
        float: left;
      }
      #right-panel {
        width: 46%;
        float: left;
      }
      #encoded-polyline {
        height: 100px;
        width: 100%;
      }
    </style>
  </head>
  <body>
    <div id="map"></div>
    <div id="right-panel">
      <div>Encoding:</div>
      <textarea id="encoded-polyline"></textarea>
    </div>
    <script>
      // This example requires the Geometry library. Include the libraries=geometry
      // parameter when you first load the API. For example:
      // <script src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&libraries=geometry">

      function initMap() {
        var map = new google.maps.Map(document.getElementById('map'), {
          zoom: 14,
          center: {lat: 34.366, lng: -89.519}
        });
        var poly = new google.maps.Polyline({
          strokeColor: '#000000',
          strokeOpacity: 1,
          strokeWeight: 3,
          map: map
        });

        // Add a listener for the click event
        google.maps.event.addListener(map, 'click', function(event) {
          addLatLngToPoly(event.latLng, poly);
        });
      }

      /**
       * Handles click events on a map, and adds a new point to the Polyline.
       * Updates the encoding text area with the path's encoded values.
       */
      function addLatLngToPoly(latLng, poly) {
        var path = poly.getPath();
        // Because path is an MVCArray, we can simply append a new coordinate
        // and it will automatically appear
        path.push(latLng);

        // Update the text field to display the polyline encodings
        var encodeString = google.maps.geometry.encoding.encodePath(path);
        if (encodeString) {
          document.getElementById('encoded-polyline').value = encodeString;
        }
      }
    </script>
    <script src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&libraries=geometry&callback=initMap"
        async defer></script>
  </body>
</html>

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