Marker Clustering

Read the documentation.

import { MarkerClusterer } from "@googlemaps/markerclusterer";

async function initMap() {
  // Request needed libraries.
  const { Map, InfoWindow } = await google.maps.importLibrary("maps") as google.maps.MapsLibrary;
  const { AdvancedMarkerElement, PinElement } = await google.maps.importLibrary("marker") as google.maps.MarkerLibrary;

  const map = new google.maps.Map(
    document.getElementById("map") as HTMLElement,
    {
      zoom: 3,
      center: { lat: -28.024, lng: 140.887 },
      mapId: 'DEMO_MAP_ID',
    }
  );

  const infoWindow = new google.maps.InfoWindow({
    content: "",
    disableAutoPan: true,
  });

  // Create an array of alphabetical characters used to label the markers.
  const labels = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

  // Add some markers to the map.
  const markers = locations.map((position, i) => {
    const label = labels[i % labels.length];
    const pinGlyph = new google.maps.marker.PinElement({
      glyph: label,
      glyphColor: "white",
    })
    const marker = new google.maps.marker.AdvancedMarkerElement({
      position,
      content: pinGlyph.element,
    });

    // markers can only be keyboard focusable when they have click listeners
    // open info window when marker is clicked
    marker.addListener("click", () => {
      infoWindow.setContent(position.lat + ", " + position.lng);
      infoWindow.open(map, marker);
    });
    return marker;
  });

  // Add a marker clusterer to manage the markers.
  new MarkerClusterer({ markers, map });
}

const locations = [
  { lat: -31.56391, lng: 147.154312 },
  { lat: -33.718234, lng: 150.363181 },
  { lat: -33.727111, lng: 150.371124 },
  { lat: -33.848588, lng: 151.209834 },
  { lat: -33.851702, lng: 151.216968 },
  { lat: -34.671264, lng: 150.863657 },
  { lat: -35.304724, lng: 148.662905 },
  { lat: -36.817685, lng: 175.699196 },
  { lat: -36.828611, lng: 175.790222 },
  { lat: -37.75, lng: 145.116667 },
  { lat: -37.759859, lng: 145.128708 },
  { lat: -37.765015, lng: 145.133858 },
  { lat: -37.770104, lng: 145.143299 },
  { lat: -37.7737, lng: 145.145187 },
  { lat: -37.774785, lng: 145.137978 },
  { lat: -37.819616, lng: 144.968119 },
  { lat: -38.330766, lng: 144.695692 },
  { lat: -39.927193, lng: 175.053218 },
  { lat: -41.330162, lng: 174.865694 },
  { lat: -42.734358, lng: 147.439506 },
  { lat: -42.734358, lng: 147.501315 },
  { lat: -42.735258, lng: 147.438 },
  { lat: -43.999792, lng: 170.463352 },
];

initMap();
import { MarkerClusterer } from "@googlemaps/markerclusterer";

async function initMap() {
  // Request needed libraries.
  const { Map, InfoWindow } = await google.maps.importLibrary("maps");
  const { AdvancedMarkerElement, PinElement } = await google.maps.importLibrary(
    "marker",
  );
  const map = new google.maps.Map(document.getElementById("map"), {
    zoom: 3,
    center: { lat: -28.024, lng: 140.887 },
    mapId: "DEMO_MAP_ID",
  });
  const infoWindow = new google.maps.InfoWindow({
    content: "",
    disableAutoPan: true,
  });
  // Create an array of alphabetical characters used to label the markers.
  const labels = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  // Add some markers to the map.
  const markers = locations.map((position, i) => {
    const label = labels[i % labels.length];
    const pinGlyph = new google.maps.marker.PinElement({
      glyph: label,
      glyphColor: "white",
    });
    const marker = new google.maps.marker.AdvancedMarkerElement({
      position,
      content: pinGlyph.element,
    });

    // markers can only be keyboard focusable when they have click listeners
    // open info window when marker is clicked
    marker.addListener("click", () => {
      infoWindow.setContent(position.lat + ", " + position.lng);
      infoWindow.open(map, marker);
    });
    return marker;
  });

  // Add a marker clusterer to manage the markers.
  new MarkerClusterer({ markers, map });
}

const locations = [
  { lat: -31.56391, lng: 147.154312 },
  { lat: -33.718234, lng: 150.363181 },
  { lat: -33.727111, lng: 150.371124 },
  { lat: -33.848588, lng: 151.209834 },
  { lat: -33.851702, lng: 151.216968 },
  { lat: -34.671264, lng: 150.863657 },
  { lat: -35.304724, lng: 148.662905 },
  { lat: -36.817685, lng: 175.699196 },
  { lat: -36.828611, lng: 175.790222 },
  { lat: -37.75, lng: 145.116667 },
  { lat: -37.759859, lng: 145.128708 },
  { lat: -37.765015, lng: 145.133858 },
  { lat: -37.770104, lng: 145.143299 },
  { lat: -37.7737, lng: 145.145187 },
  { lat: -37.774785, lng: 145.137978 },
  { lat: -37.819616, lng: 144.968119 },
  { lat: -38.330766, lng: 144.695692 },
  { lat: -39.927193, lng: 175.053218 },
  { lat: -41.330162, lng: 174.865694 },
  { lat: -42.734358, lng: 147.439506 },
  { lat: -42.734358, lng: 147.501315 },
  { lat: -42.735258, lng: 147.438 },
  { lat: -43.999792, lng: 170.463352 },
];

initMap();
/* 
 * Always set the map height explicitly to define the size of the div element
 * that contains the map. 
 */
#map {
  height: 100%;
}

/* 
 * Optional: Makes the sample page fill the window. 
 */
html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}
<html>
  <head>
    <title>Marker Clustering</title>

    <link rel="stylesheet" type="text/css" href="./style.css" />
    <script type="module" src="./index.js"></script>
  </head>
  <body>
    <div id="map"></div>

    <!-- prettier-ignore -->
    <script>(g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))})
        ({key: "AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg", v: "weekly"});</script>
  </body>
</html>

Try Sample

Clone Sample

Git and Node.js are required to run this sample locally. Follow these instructions to install Node.js and NPM. The following commands clone, install dependencies and start the sample application.

  git clone -b sample-marker-clustering https://github.com/googlemaps/js-samples.git
  cd js-samples
  npm i
  npm start

Other samples can be tried by switching to any branch beginning with sample-SAMPLE_NAME.

  git checkout sample-SAMPLE_NAME
  npm i
  npm start