Geocoding

geocode() turns an address or a place name into coordinates. It tolerates typos and partial addresses, and covers street addresses, intersections and areas from neighbourhoods to countries. It returns no POIs. To find a business or a landmark, use discoverPlaces().

Basic geocoding usage

Simplest single address geocoding

geocodeOne returns the best match, and throws an Error when there is none:

import { geocodeOne } from '@tomtom-org/maps-sdk/services';

const place = await geocodeOne('Dam Square, Amsterdam, Netherlands');
const coordinates = place.geometry.coordinates; // [longitude, latitude]

// The params form takes everything `geocode` does except `limit`
const biased = await geocodeOne({ query: 'Main Street', geoBias: { position: [4.9041, 52.3676] } });

Standard address geocoding

geocode returns every candidate. If nothing matches, it returns an empty collection instead of an error:

import { geocode } from '@tomtom-org/maps-sdk/services';

const result = await geocode({ query: 'Dam Square, Amsterdam, Netherlands' });

const coordinates = result.features[0]?.geometry.coordinates; // [longitude, latitude]

Filtering results

filters holds every option that drops results, by country and by geography type.

const result = await geocode({
    query: 'Utrecht',
    filters: { countries: ['NL'], geographyTypes: ['Municipality'] },
});

• countries - Takes ISO 3166-1 alpha-2 or alpha-3 codes.
• geographyTypes - Restricts Geography results to types such as Municipality or PostalCodeArea.
• There are no POI filters. Geocoding has no notion of POIs, so the rest of search's filters doesn't apply.

Advanced geocoding configuration

Geographic constraints and biasing

geoBias takes a point or a rectangle, as it does for search. A point ranks nearer results higher, and with radiusMeters it confines them to a circle. A rectangle confines them to its area.

const nearAmsterdam = await geocode({
    query: 'Central Station',
    geoBias: { position: [4.9041, 52.3676] },
    filters: { countries: ['NL'] },
});

const inBox = await geocode({
    query: 'Main Street',
    geoBias: { boundingBox: [4.7, 52.2, 5.1, 52.5] }, // [minLng, minLat, maxLng, maxLat]
});

Other parameters

Besides query, limit (up to 100, default 10), filters, geoBias and cursor, geocoding takes these parameters and the options every service call takes:

The full type is GeocodingParams.

Geopolitical view

geopoliticalView decides which country an address in a disputed territory belongs to, and defaults to the global one. Geocoding supports fewer views than the other places services. For a view it doesn't support, it uses the default for the caller's country. Geopolitical views lists them.

const result = await geocode({ query: 'Laayoune', geopoliticalView: 'MA' });

Multiple result handling

An ambiguous name returns several candidates, so the user can pick one:

const results = await geocode({ query: 'Paris', limit: 5 });

results.features.forEach((place) => {
    const { municipality, country } = place.properties.address;
    console.log(`${municipality}, ${country}`, place.geometry.coordinates);
});

// The next five, if there are any
const nextCursor = results.properties?.nextCursor;
const more = nextCursor && (await geocode({ query: 'Paris', limit: 5, cursor: nextCursor }));

To fetch the next page, pass the response's properties.nextCursor back as cursor with the same parameters, as in search pagination.

Working with geocoding results

Result data structure

Each feature is a Place whose type is an address, a street, a cross street or a Geography, never a POI. Besides the place properties, it carries matchConfidence.score, which says how well the result's text matches the query:

const result = await geocode({ query: 'Damrak 1, Amsterdam' });
const place = result.features[0];

const [longitude, latitude] = place.geometry.coordinates;
const { freeformAddress, streetName, streetNumber, municipality, postalCode, country } = place.properties.address;

console.log(place.properties.type);                  // e.g. 'Point Address'
console.log(place.properties.matchConfidence.score); // higher is a closer textual match

Address lists every address component.

Integration with mapping

The Places module shows the result as it is:

import { TomTomMap, PlacesModule } from '@tomtom-org/maps-sdk/map';
import { geocode } from '@tomtom-org/maps-sdk/services';

const map = new TomTomMap({ mapLibre: { container: 'map' } });
const placesModule = await PlacesModule.create(map);

await placesModule.show(await geocode({ query: 'Museumplein, Amsterdam' }));

Performance and best practices

• When you know the country or the area, narrow the search with filters and a geoBias. Results get more relevant and ambiguous names resolve.
• Cache frequent lookups yourself, since the SDK doesn't.
• Handle no match, which is an empty collection from geocode or a thrown Error from geocodeOne. A failed request rejects with an SDKError. Error handling covers its kinds.

Related guides and examples

Map integration

• Places module - Geocoded locations on the map
• Routing module - Geocoded addresses as route waypoints

Related examples

• Geocode - An address to coordinates, on the map
• Geocode start location - A map opened on a geocoded region's bbox
• Waypoints - Geocoded addresses as route waypoints
• Map route reconstruction playground - A route between geocoded locations, reshaped by a drawn trail

Related services

• Reverse geocoding - Coordinates to an address
• Discover places - POIs and free-text search
• Route planning parameters - Routes between geocoded locations