Reverse geocode

Learn how to find an address near a location.

Reverse geocode coordinates to addresses with the geocoding service using API key authentication

The ArcGIS Geocoding service allows you to perform reverse geocode. Reverse geocoding is the process of converting a location to an address or place. This operation requires an initial location and returns an address with attributes such as place name and location.

In this tutorial, use the MapLibre ArcGIS plugin to display a map and ArcGIS REST JS to reverse geocode and find the closest address to your clicked location on the map.

Prerequisites

You need an ArcGIS Location Platform or ArcGIS Online account.

Steps

Get the starter app

Select a type of authentication below and follow the steps to create a new application.

You can choose one of the following to create a new CodePen:

Option 1: Complete the Display a map tutorial; or,
Option 2: Start from the Display a map tutorial .

Set up authentication

Create developer credentials in your portal for the type of authentication you selected.

Create a new API key credential with the correct privileges to access the resources used in this tutorial.

Go to the Create an API key tutorial to follow the steps to get an access token with these privilege(s):
- Privileges
  - Location services > Basemaps
  - Location services > Geocoding

Set developer credentials

Use the API key or OAuth developer credentials so your application can access ArcGIS services.

Update the accessToken variable to use your API key.

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    /* Use for API key authentication */
    const accessToken = "YOUR_ACCESS_TOKEN";
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In both the index.html and callback.html files, replace YOUR_CLIENT_ID and YOUR_REDIRECT_URL with the client ID and redirect URL of your OAuth credentials.

index.html
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    /* Use for user authentication */
    const clientId = "YOUR_CLIENT_ID"; // Your client ID from OAuth credentials
    const redirectUri = "YOUR_REDIRECT_URI"; // The redirect URL registered in your OAuth credentials
    const session = await arcgisRest.ArcGISIdentityManager.beginOAuth2({
        clientId,
        redirectUri,
        portal: "https://www.arcgis.com/sharing/rest" // Your portal URL
    });

    const accessToken = session.token;

callback.html
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    arcgisRest.ArcGISIdentityManager.completeOAuth2({
      clientId: "YOUR_CLIENT_ID", // Your client ID from OAuth credentials
      redirectUri: "YOUR_REDIRECT_URI", // The redirect URL registered in your OAuth credentials
      portal: "https://www.arcgis.com/sharing/rest" // Your portal URL
    });

Run the app and ensure you can sign in successfully.

If you are unable to sign in, make sure you have the correct redirect URL and port. This URL varies based on your application and typically takes the format of https://<server>[:port]/callback.html or http://my-arcgis-app:/auth. For example, if you are running an application on http://127.0.0.1:5500/, set http://127.0.0.1:5500/callback.html as your redirect URL in the index.html and callback.html file and your developer credential. They all have to match!

Add references to ArcGIS REST JS

This tutorial uses ArcGIS REST JS for reverse geocoding.

In the <head> element, add references to the ArcGIS REST JS library.

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  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
    <!-- Load MapLibre GL JS from CDN -->
    <script src=https://unpkg.com/maplibre-gl@5.9.0/dist/maplibre-gl.js></script>
    <link href=https://unpkg.com/maplibre-gl@5.9.0/dist/maplibre-gl.css rel="stylesheet" />
    <!-- Load MapLibre ArcGIS from CDN -->
    <script src="https://unpkg.com/@esri/maplibre-arcgis@1.0.0/dist/umd/maplibre-arcgis.min.js"></script>

    <script src="https://unpkg.com/@esri/arcgis-rest-request@4/dist/bundled/request.umd.js"></script>
    <script src="https://unpkg.com/@esri/arcgis-rest-geocoding@4/dist/bundled/geocoding.umd.js"></script>
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Update the map

An arcgis/navigation basemap style is typically used in geocoding and routing applications. Update the basemap layer to use the style.

Update the basemap and the map initialization to center on location [2.3522,48.8566], Paris.

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  <script>

    /* Use for API key authentication */
    const accessToken = "YOUR_ACCESS_TOKEN";

    // or

    /* Use for user authentication */
    // const session = await arcgisRest.ArcGISIdentityManager.beginOAuth2({
    //   clientId: "YOUR_CLIENT_ID", // Your client ID from OAuth credentials
    //   redirectUri: "YOUR_REDIRECT_URI", // The redirect URL registered in your OAuth credentials
    //   portal: "YOUR_PORTAL_URL" // Your portal URL
    // })

    // const accessToken = session.token;

    const map = new maplibregl.Map({
      container: "map",
      zoom: 12,

      center: [2.3522, 48.8566] // Paris

    });

    const basemapStyle = maplibreArcGIS.BasemapStyle.applyStyle(map, {
      style: 'arcgis/navigation',
      token: accessToken
    });

  </script>
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Add a click event handler

Before you call the Geocoding service, you need to get a location from the user. You can add a handler to the Map's click event. The click handler will be called with an object containing parameters such as lngLat.

The lngLat property is a LngLat. It has lng and lat properties and a toArray method which returns an array in [longitude, latitude] order.

After the map initialization code, add a handler for the click event. Create a coordinates array from the lngLat property of the event parameter.

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  <script>

    /* Use for API key authentication */
    const accessToken = "YOUR_ACCESS_TOKEN";

    // or

    /* Use for user authentication */
    // const session = await arcgisRest.ArcGISIdentityManager.beginOAuth2({
    //   clientId: "YOUR_CLIENT_ID", // Your client ID from OAuth credentials
    //   redirectUri: "YOUR_REDIRECT_URI", // The redirect URL registered in your OAuth credentials
    //   portal: "YOUR_PORTAL_URL" // Your portal URL
    // })

    // const accessToken = session.token;

    const map = new maplibregl.Map({
      container: "map",
      zoom: 12,

      center: [2.3522, 48.8566] // Paris

    });

    const basemapStyle = maplibreArcGIS.BasemapStyle.applyStyle(map, {
      style: 'arcgis/navigation',
      token: accessToken
    });

    map.on("click", (e) => {
      const coords = e.lngLat.toArray();

    });

  </script>
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Call the service

Use the ArcGIS REST JS reverseGeocode method to find an address closest to a point.

Inside the click handler, call the arcgisRest.reverseGeocode method and pass in the coordinates array.

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    map.on("click", (e) => {
      const coords = e.lngLat.toArray();

      const authentication = arcgisRest.ApiKeyManager.fromKey(accessToken);

      arcgisRest
        .reverseGeocode(coords, {
          authentication
        })
        .then((result) => {

    });
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Display the result

The response from the reverseGeocode operation contains two properties. address is a structured object with fields such as street name and business name. location contains the location of the returned address, which may differ from the coordinates you provided.

Use the results to display a pop-up with the address and location values.

Convert the result.location object into an array of [longitude, latitude].

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      arcgisRest
        .reverseGeocode(coords, {
          authentication
        })
        .then((result) => {

          const lngLat = [result.location.x, result.location.y];

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Set a variable containing the text you want to display, using the address and coordinates.

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          const lngLat = [result.location.x, result.location.y];

          const label = `${result.address.LongLabel}<br>${lngLat[0].toLocaleString()}, ${lngLat[1].toLocaleString()}`;

        })
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Add a pop-up to display the label at the returned coordinates.

To add a pop-up to the map, you use the Popup class in MapLibre GL JS. See the Display a pop-up tutorial for more information.

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          const lngLat = [result.location.x, result.location.y];

          const label = `${result.address.LongLabel}<br>${lngLat[0].toLocaleString()}, ${lngLat[1].toLocaleString()}`;

          new maplibregl.Popup().setLngLat(lngLat).setHTML(label).addTo(map);

        })
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Handle errors

To handle errors that occur when accessing the Geocoding service, such as networking or API key issues, use an error handler to show a message to the user.

Add a handler to catch any exception and display a message to the user.

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      const authentication = arcgisRest.ApiKeyManager.fromKey(accessToken);

      arcgisRest
        .reverseGeocode(coords, {
          authentication
        })
        .then((result) => {

          const lngLat = [result.location.x, result.location.y];

          const label = `${result.address.LongLabel}<br>${lngLat[0].toLocaleString()}, ${lngLat[1].toLocaleString()}`;

          new maplibregl.Popup().setLngLat(lngLat).setHTML(label).addTo(map);

        })

        .catch((error) => {
          alert("There was a problem using the reverse geocode service. See the console for details.");
          console.error(error);
        });
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Run the app

Run the app.

Click on the map to reverse geocode the clicked point and display a pop-up with the closest address and coordinates.

What's next?

Learn how to use additional location services in these tutorials:

Search with autosuggest

Search for addresses with partial text using autosuggest.

Find place addresses

Search for places by category near a location.

Find a route and directions

Find a route and directions from a start and finish location.