---
title: "Create and style clusters | JavaScript maps SDK"
description: "Visualize point data as clusters using built-in SDK functions."
---

> For AI agents: a documentation index is available at [/llms.txt](https://docs.maptiler.com/llms.txt). Markdown versions of all pages are available by appending .md to any URL.

# Create and style clusters

The following example utilizes the built-in functions of the SDK JS to generate a cluster map of points and visualize them.

### NPM module setup

```bash
npm install --save @maptiler/sdk
```

#### main.js

```js
import { Map, MapStyle, config } from '@maptiler/sdk';
import '@maptiler/sdk/dist/maptiler-sdk.css';

config.apiKey = 'YOUR_MAPTILER_API_KEY_HERE';
const map = new Map({
    container: 'map',
    zoom: 0.3,
    center: [0, 20],
    style: MapStyle.DATAVIZ.DARK
});

  map.on('load', function () {
    // add a clustered GeoJSON source for a sample set of earthquakes
    map.addSource('earthquakes', {
      'type': 'geojson',
      'data': 'https://docs.maptiler.com/sdk-js/assets/earthquakes.geojson',
      cluster: true,
      clusterMaxZoom: 14, // Max zoom to cluster points on
      clusterRadius: 50 // Radius of each cluster when clustering points (defaults to 50)
    });

    map.addLayer({
      id: 'clusters',
      type: 'circle',
      source: 'earthquakes',
      filter: ['has', 'point_count'],
      paint: {
        // Use step expressions (https://docs.maptiler.com/gl-style-specification/expressions/#step)
        // with three steps to implement three types of circles:
        //   * Blue, 20px circles when point count is less than 100
        //   * Yellow, 30px circles when point count is between 100 and 750
        //   * Pink, 40px circles when point count is greater than or equal to 750
        'circle-color': [
          'step',
          ['get', 'point_count'],
          '#51bbd6',
          100,
          '#f1f075',
          750,
          '#f28cb1'
        ],
        'circle-radius': [
          'step',
          ['get', 'point_count'],
          20,
          100,
          30,
          750,
          40
        ]
      }
    });

    map.addLayer({
      id: 'cluster-count',
      type: 'symbol',
      source: 'earthquakes',
      filter: ['has', 'point_count'],
      layout: {
        'text-field': '{point_count_abbreviated}',
        'text-font': ['DIN Offc Pro Medium', 'Arial Unicode MS Bold'],
        'text-size': 12
      }
    });

    map.addLayer({
      id: 'unclustered-point',
      type: 'circle',
      source: 'earthquakes',
      filter: ['!', ['has', 'point_count']],
      paint: {
        'circle-color': '#11b4da',
        'circle-radius': 4,
        'circle-stroke-width': 1,
        'circle-stroke-color': '#fff'
      }
    });

    // inspect a cluster on click
    map.on('click', 'clusters', async function (e) {
      const features = map.queryRenderedFeatures(e.point, {
        layers: ['clusters']
      });
      const clusterId = features[0].properties.cluster_id;
      const zoom = await map.getSource('earthquakes').getClusterExpansionZoom(clusterId);
      map.easeTo({
        center: features[0].geometry.coordinates,
        zoom
      });
    });

    // When a click event occurs on a feature in
    // the unclustered-point layer, open a popup at
    // the location of the feature, with
    // description HTML from its properties.
    map.on('click', 'unclustered-point', function (e) {
      const coordinates = e.features[0].geometry.coordinates.slice();
      const mag = e.features[0].properties.mag;
      let tsunami;

      if (e.features[0].properties.tsunami === 1) {
        tsunami = 'yes';
      } else {
        tsunami = 'no';
      }

      // Ensure that if the map is zoomed out such that
      // multiple copies of the feature are visible, the
      // popup appears over the copy being pointed to.
      while (Math.abs(e.lngLat.lng - coordinates[0]) > 180) {
        coordinates[0] += e.lngLat.lng > coordinates[0] ? 360 : -360;
      }

      new maptilersdk.Popup()
        .setLngLat(coordinates)
        .setHTML(
          'magnitude: ' + mag + '<br>Was there a tsunami?: ' + tsunami
        )
        .addTo(map);
    });

    map.on('mouseenter', 'clusters', function () {
      map.getCanvas().style.cursor = 'pointer';
    });
    map.on('mouseleave', 'clusters', function () {
      map.getCanvas().style.cursor = '';
    });
    map.on('mouseenter', 'unclustered-point', function () {
      map.getCanvas().style.cursor = 'pointer';
    });
    map.on('mouseleave', 'unclustered-point', function () {
      map.getCanvas().style.cursor = '';
    });
  });
```

#### index.html

```html
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="robots" content="noindex">
  <title>Create and style clusters | NPM example</title>
  <link rel="stylesheet" href="./style.css">
</head>
<body>
  <div id="map"></div>
  <script type="module" src="./main.js"></script>
</body>
</html>
```

#### style.css

```css
body {margin: 0; padding: 0;}
#map {position: absolute; top: 0; bottom: 0; width: 100%;}
```

### Basic JavaScript setup

```html
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Create and style clusters</title>
<script src="https://cdn.maptiler.com/maptiler-sdk-js/v4.2.0/maptiler-sdk.umd.min.js"></script>
<link href="https://cdn.maptiler.com/maptiler-sdk-js/v4.2.0/maptiler-sdk.css" rel="stylesheet" />
<style>
  body {margin: 0; padding: 0;}
  #map {position: absolute; top: 0; bottom: 0; width: 100%;}
</style>
</head>
<body>
<div id="map"></div>

<script>
    maptilersdk.config.apiKey = 'YOUR_MAPTILER_API_KEY_HERE';
    const map = new maptilersdk.Map({
        container: 'map',
        zoom: 0.3,
        center: [0, 20],
        style: maptilersdk.MapStyle.DATAVIZ.DARK
    });

      map.on('load', function () {
        // add a clustered GeoJSON source for a sample set of earthquakes
        map.addSource('earthquakes', {
          'type': 'geojson',
          'data': 'https://docs.maptiler.com/sdk-js/assets/earthquakes.geojson',
          cluster: true,
          clusterMaxZoom: 14, // Max zoom to cluster points on
          clusterRadius: 50 // Radius of each cluster when clustering points (defaults to 50)
        });

        map.addLayer({
          id: 'clusters',
          type: 'circle',
          source: 'earthquakes',
          filter: ['has', 'point_count'],
          paint: {
            // Use step expressions (https://docs.maptiler.com/gl-style-specification/expressions/#step)
            // with three steps to implement three types of circles:
            //   * Blue, 20px circles when point count is less than 100
            //   * Yellow, 30px circles when point count is between 100 and 750
            //   * Pink, 40px circles when point count is greater than or equal to 750
            'circle-color': [
              'step',
              ['get', 'point_count'],
              '#51bbd6',
              100,
              '#f1f075',
              750,
              '#f28cb1'
            ],
            'circle-radius': [
              'step',
              ['get', 'point_count'],
              20,
              100,
              30,
              750,
              40
            ]
          }
        });

        map.addLayer({
          id: 'cluster-count',
          type: 'symbol',
          source: 'earthquakes',
          filter: ['has', 'point_count'],
          layout: {
            'text-field': '{point_count_abbreviated}',
            'text-font': ['DIN Offc Pro Medium', 'Arial Unicode MS Bold'],
            'text-size': 12
          }
        });

        map.addLayer({
          id: 'unclustered-point',
          type: 'circle',
          source: 'earthquakes',
          filter: ['!', ['has', 'point_count']],
          paint: {
            'circle-color': '#11b4da',
            'circle-radius': 4,
            'circle-stroke-width': 1,
            'circle-stroke-color': '#fff'
          }
        });

        // inspect a cluster on click
        map.on('click', 'clusters', async function (e) {
          const features = map.queryRenderedFeatures(e.point, {
            layers: ['clusters']
          });
          const clusterId = features[0].properties.cluster_id;
          const zoom = await map.getSource('earthquakes').getClusterExpansionZoom(clusterId);
          map.easeTo({
            center: features[0].geometry.coordinates,
            zoom
          });
        });

        // When a click event occurs on a feature in
        // the unclustered-point layer, open a popup at
        // the location of the feature, with
        // description HTML from its properties.
        map.on('click', 'unclustered-point', function (e) {
          const coordinates = e.features[0].geometry.coordinates.slice();
          const mag = e.features[0].properties.mag;
          let tsunami;

          if (e.features[0].properties.tsunami === 1) {
            tsunami = 'yes';
          } else {
            tsunami = 'no';
          }

          // Ensure that if the map is zoomed out such that
          // multiple copies of the feature are visible, the
          // popup appears over the copy being pointed to.
          while (Math.abs(e.lngLat.lng - coordinates[0]) > 180) {
            coordinates[0] += e.lngLat.lng > coordinates[0] ? 360 : -360;
          }

          new maptilersdk.Popup()
            .setLngLat(coordinates)
            .setHTML(
              'magnitude: ' + mag + '<br>Was there a tsunami?: ' + tsunami
            )
            .addTo(map);
        });

        map.on('mouseenter', 'clusters', function () {
          map.getCanvas().style.cursor = 'pointer';
        });
        map.on('mouseleave', 'clusters', function () {
          map.getCanvas().style.cursor = '';
        });
        map.on('mouseenter', 'unclustered-point', function () {
          map.getCanvas().style.cursor = 'pointer';
        });
        map.on('mouseleave', 'unclustered-point', function () {
          map.getCanvas().style.cursor = '';
        });
      });

</script>
</body>
</html>
```

## Related examples

### [HTML clusters with custom properties](https://docs.maptiler.com/sdk-js/examples/cluster-html/)

Examples

Enhance map clustering using HTML markers and custom expressions.

### [Point layer cluster (point helper)](https://docs.maptiler.com/sdk-js/examples/helper-point-cluster/)

Examples

Add clustered point layer using MapTiler point helper.

### [Heatmap layer (heatmap helper)](https://docs.maptiler.com/sdk-js/examples/helper-heatmap-minimal/)

Examples

Quickly add a heatmap layer using the heatmap helper.

### [Point filtering by property](https://docs.maptiler.com/sdk-js/examples/point-filtering/)

Examples

Filter features in real time by property.