Tutorials | what3words
We use cookies, including third party cookies, to improve your experience and for marketing purposes. By continuing to browse we assume you have consented to their use.Learn more
got it
All tutorials

JavaScript

intermediate

The JavaScript API wrapper is useful for JavaScript developers who wish to seamlessly integrate the what3words API into their JavaScript applications, without the hassle of having to manage the low level API calls themselves.

The what3words API is a fast, simple interface which allows you to convert 3 word addresses such as ///index.home.raft to latitude and longitude coordinates such as (-0.203586, 51.521251) and vice versa. It features a powerful autosuggest function, which can validate and autocorrect user input and limit it to certain geographic areas (this powers the search box on our map site). It allows you to request a section of the what3words grid (which can be requested as GeoJSON for easy display on online maps), and to request the list of all languages supported by what3words. For advanced users, autosuggest can be used to post-process voice output. See links on the left to navigate.

All coordinates are latitude,longitude pairs in standard WGS-84 (as commonly used worldwide in GPS systems). All latitudes must be in the range of -90 to 90 (inclusive).

You will need a what3words API key to complete this tutorial.

2

Installation

To load the what3words JavaScript API, use a script tag like the one in the following example:

<script src="https://assets.what3words.com/sdk/v3/what3words.js?key=YOUR_API_KEY"></script>
Copied

The URL contained in the script tag is the location of a JavaScript file that loads everything you need for using the JavaScript wrapper for the what3words API.

The key parameter contains your application’s API key. Sign up to obtain your free API key.

3

Usage

Convert to 3 word address

Convert coordinates, expressed as latitude and longitude to a 3 word address.

More info about convertTo3wa, including returned results is available in the what3words REST API documentation.

Return standard response:

what3words.api.convertTo3wa({lat:51.508344, lng:-0.12549900}).then(function(response) {
   console.log("[convertTo3wa]", response);
});
Copied

Return as GeoJSON:

what3words.api.convertTo3waGeoJson({lat:51.508344, lng:-0.12549900}).then(function(response) {
   console.log("[convertTo3wa]", response);
});
Copied

Convert to coordinates

This function converts a 3 word address to a position (expressed as coordinates of latitude and longitude).

It takes the words parameter as a string of 3 words 'table.book.chair'

More info about convertToCoordinates, including returned results is available in the what3words REST API documentation.

Return standard response:

what3words.api.convertToCoordinates("filled.count.soap").then(function(response) {
   console.log("[convertToCoordinates]", response);
});
Copied

Return as GeoJSON:

what3words.api.convertToCoordinatesGeoJson({lat:51.508344, lng:-0.12549900}).then(function(response) {
   console.log("[convertTo3wa]", response);
});
Copied

AutoSuggest

When presented with a 3 words address which may be incorrectly entered, AutoSuggest returns a list of potential correct 3 word addresses. It needs the first two words plus at least the first character of the third word to produce suggestions.

This method provides corrections for mis-typed words (including plural VS singular), and words being in the wrong order.

Optionally, clipping can narrow down the possibilities, and limit results to:

  • One or more countries
  • A geographic area (a circle, box or polygon)

This dramatically improves results, so we recommend that you use clipping if possible.

To improve results even further, set the focus to user’s current location. This will make autosuggest return results which are closer to the user.

More information about autosuggest, including returned results is available in the what3words REST API documentation.

Example: Basic Autosuggest call

what3words.api.autosuggest("fun.with.code").then(function(response) {
   console.log("[autosuggest]", response);
});
Copied

Example: AutoSuggest, clipping the results returned to France and Germany

what3words.api.autosuggest("fun.with.code", { clipToCountry: ["FR", "DE"] })
  .then(function(response) {
    console.log("[autosuggest]", response);
  }
);
Copied

Example: AutoSuggest, clipping to a circle

what3words.api.autosuggest("fun.with.code", { clipToCircle: {center: {lat:51.4243877, lng:-0.34745}, radius:50} })
  .then(function(response) {
    console.log("[autosuggest]", response);
  }
);
Copied

Example: AutoSuggest, clipping to a polygon

what3words.api.autosuggest("fun.with.code", { clipToPolygon: [51.421,-0.343,52.6,2.3324,54.234,8.343,51.421,-0.343] })
  .then(function(response) {
    console.log("[autosuggest]", response);
  }
);
Copied

Example: AutoSuggest, clipping to a bounding box

what3words.api.autosuggest("fun.with.code", { clipToBoundingBox:{ southwest: { lat: 51.521, lng: -0.343 },
    northeast: { lat: 52.6, lng: 2.3324 } }})
  .then(function(response) {
    console.log("[autosuggest]", response);
  }
);
Copied

Example: AutoSuggest, Focus on (51.4243877,-0.34745)

what3words.api.autosuggest("fun.with.code", { focus: {lat:51.4243877, lng:-0.34745} })
  .then(function(response) {
    console.log("[autosuggest]", response);
  }
);
Copied

Example: AutoSuggest, Focus on (51.4243877,-0.34745) and then determine how many results within the response it applies to

what3words.api.autosuggest("fun.with.code", {focus: {lat:51.4243877, lng:-0.34745},nFocusResults: 2})
  .then(function(response) {
    console.log("[autosuggest]", response);
  }
);
Copied

Example: AutoSuggest, with Generic Voice input type

what3words.api.autosuggest("fun with code", {inputType: "generic-voice", language: "en"})
  .then(function(response) {
    console.log("[autosuggest]", response);
  }
);
Copied

Grid section

Grid section returns a section of the what3words 3m x 3m grid as a set of horizontal and vertical lines covering the requested area, which can then be drawn onto a map.

The requested box must not exceed 4km from corner to corner, or a BadBoundingBoxTooBig error will be returned.

More information about gridSection, including returned results is available in the what3words REST API documentation.

Return standard response:

what3words.api.gridSection({
    southwest: { lat: 51.508341, lng: -0.125499 },
    northeast: { lat: 51.507341, lng: -0.124499 }
  })
  .then(function(response) {
    console.log("[gridSection]", response);
  }
);
Copied

Return as GeoJSON:

what3words.api.gridSectionGeoJson({
    southwest: { lat: 51.508341, lng: -0.125499 },
    northeast: { lat: 51.507341, lng: -0.124499 }
  })
  .then(function(response) {
    console.log("[gridSection]", response);
  }
);
Copied

Available languages

This function returns the currently supported languages. It will return the two letter code, and the name of the language both in that language and in English.

More information about availableLanguages, including returned results is available in the what3words REST API documentation.

what3words.api.availableLanguages().then(function(n) {
  console.log("[availableLanguages]",n)
});
Copied

Handling errors

Errors returned from the API can be caught with the wrapper through the use of a catch function.

Within the catch function, code and message values which represent the error, are accessible from the error object parameter

what3words.api.convertToCoordinates("filled.count.soap")
  .then(function(response) {
    console.log("[convertToCoordinates]", response);
  })
  .catch(function(error) { // catch errors here
    console.log("[code]", error.code);
    console.log("[message]", error.message);
  });
Copied

Related tutorials

Back to top