Google Maps Basic

Create a Basic Google Map

This example creates a Google Map centered in London, England:

Example

<!DOCTYPE html>
<html>
<head>
<script src="http://maps.googleapis.com/maps/api/js"></script>
<script>
function initialize() {
var mapProp = {
    center:new google.maps.LatLng(51.508742,-0.120850),
    zoom:5,
    mapTypeId:google.maps.MapTypeId.ROADMAP
};
var map=new google.maps.Map(document.getElementById("googleMap"),mapProp);
}
google.maps.event.addDomListener(window, 'load', initialize);
</script>
</head>

<body>
<div id="googleMap" style="width:500px;height:380px;"></div>
</body>

</html>

Try it Yourself »

The rest of this page describes the example above, step by step.

1. Load the Google API

The Google Maps API is a JavaScript library. It can be added to a web page with a <script> tag:

2. Set Map Properties

Create a function to initialize the map:

function initialize() {
}

In the initialize function, create an object (mapProp) to define the properties for the map:

var mapProp = {
center:new google.maps.LatLng(51.508742, -0.120850),
zoom: 7,
mapTypeId: google.maps.MapTypeId.ROADMAP
};

The center property specifies where to center the map. Create a LatLng object to center the map on a specific point. Pass the coordinates in the order: latitude, longitude.

The zoom property specifies the zoom level for the map. zoom: 0 shows a map of the Earth fully zoomed out. Higher zoom levels zoom in at a higher resolution.

The mapTypeId property specifies the map type to display. The following map types are supported:

ROADMAP (normal, default 2D map)
SATELLITE (photographic map)
HYBRID (photographic map + roads and city names)
TERRAIN (map with mountains, rivers, etc.)

3. Create a Map Container

Create a <div> element to hold the map. Use CSS to size the element:

The map will always "inherit" its size from its container element.

4. Create a Map Object

var map=new google.maps.Map(document.getElementById("googleMap"), mapProp);

The code above creates a new map inside the <div> element with id="googleMap", using the parameters that are passed (mapProp).

5. Add an Event Listener to Load the Map

Add a DOM listener that will execute the initialize() function on window load (when the page is loaded):

google.maps.event.addDomListener(window, 'load', initialize);

Asynchronously Loading

It is also possible to load the Google Maps API on demand.

The example below uses window.onload to load the Google Maps API after the page has fully loaded.

The loadScript() function creates the Google Maps API <script> tag. In addition, the callback=initialize parameter is added to the end of the URL to execute the initialize() function after the API is fully loaded:

Example

function loadScript() {
var script = document.createElement("script");
script.src = "http://maps.googleapis.com/maps/api/js?callback=initialize";
document.body.appendChild(script);
}

window.onload = loadScript;

Try it Yourself »

Multiple Maps

The example below defines four maps on one web page (four maps with different map types):

Example

var map1 = new google.maps.Map(document.getElementById("googleMap1"), mapProp1);
var map2 = new google.maps.Map(document.getElementById("googleMap2"), mapProp2);
var map3 = new google.maps.Map(document.getElementById("googleMap3"), mapProp3);
var map4 = new google.maps.Map(document.getElementById("googleMap4"), mapProp4);

Try it Yourself »

Google API Key

Google allows your web site to call any Google API, many thousand times per day.

If you plan for heavier traffic, you should get a free API key from Google.

Go to https://console.developers.google.com to get a free key.

Google Maps expects to find the API key in the key parameter when loading an API:

❮ Previous Next Chapter ❯