Show Polygon data from GeoJSON on the Map

This tutorial shows how to add a Polygon GeoJSON overlay to the map using OpenLayers.

NPM module
Basic JavaScript

Copy the following code, paste it into your favorite text editor, and save it as a .html file.

Check out the step-by-step tutorial How to use OpenLayers

Install the npm package.
Include the CSS file.

If you have a bundler that can handle CSS, you can import the CSS or include it with a <link> in the head of the document via the CDN
Include the following code in your JavaScript file (Example: main.js).

Replace YOUR_MAPTILER_API_KEY_HERE with your actual MapTiler API key.
The next is up to you. You can center your map wherever you desire (modifying the starting position) and set an appropriate zoom level (modifying the starting zoom) to match your users’ needs. Additionally, you can change the map’s look (by updating the source URL); choose from a range of visually appealing map styles from our extensive MapTiler standard maps, or create your own to truly differentiate your application.

Create GeoJSON source. The following snippet creates GeoJSON source hosted on MapTiler (check out the How to Upload GeoJSON to MapTiler tutorial). Publish the dataset and copy link to the geojson. Download the Rio de Janeiro sample data.


     });
   const layer = new ol.layer.Vector({
     source: new ol.source.Vector({
       url: `https://api.maptiler.com/data/YOUR_MAPTILER_DATASET_ID_HERE/features.json?key=${key}`,
       format: new ol.format.GeoJSON(),
     }),
     style: new ol.style.Style({
       stroke: new ol.style.Stroke({
         color: 'rgba(0, 136, 136, 0.8)',
       }),
       fill: new ol.style.Fill({
         color: 'rgba(0, 136, 136, 0.8)',
       }),
     })
   });
   map.addLayer(layer);

View complete source code

Import the new modules needed to add the new functionality.


 import VectorLayer from 'ol/layer/Vector.js';
 import VectorSource from 'ol/source/Vector.js';
 import Style from 'ol/style/Style.js';
 import Stroke from 'ol/style/Stroke.js';
 import Fill from 'ol/style/Fill.js';
 import GeoJSON from 'ol/format/GeoJSON.js';

Create GeoJSON layer. The following snippet creates GeoJSON layer from an external file with polygon geometry. Check out the How to Upload GeoJSON to MapTiler tutorial. Publish the dataset and copy link to the geojson. Download the Rio de Janeiro sample data.