HTML Image Maps

With HTML image-maps, you can create clickable areas on an image.

Image Maps

The <map> tag defines an image-map. An image-map is an image with clickable areas.

Click on the computer, the phone, or the cup of coffee in the image below:

How Does it Work?

The idea behind an image map is that you should be able to perform different actions depending on where in the image you click.

To create an image map you need an image, and a map containing some rules that describe the clickable areas.

The Image

The image is inserted using the <img> tag. The only difference from other images is that you must add a usemap attribute:

The usemap value starts with a hash tag # followed by the name of the image map, and is used to create a relationship between the image and the image map.

The Map

Then add a <map> element.

The <map> element is used to create an image map, and is linked to the image by using the name attribute:

The name attribute must have the same value as the usemap attribute.

The Areas

Then add the clickable areas.

A clickable area is defined using an <area> element.

Shape

You must define the shape of the area, and you can choose one of these values:

• rect - defines a rectangular region
• circle - defines a circular region
• poly - defines a polygonal region
• default - defines the entire region

Coordinates

You must define some coordinates to be able to place the clickable area onto the image.

The coordinates come in pairs, one for the x-axis and one for the y-axis.

The coordinates 34, 44 is located 34 pixels from the left margin and 44 pixels from the top:

The coordinates 270, 350 is located 270 pixels from the left margin and 350 pixels from the top:

Now you have enough data to create a clickable rectangular area:

This is the area that becomes clickable and will send the user to the page computer.htm:

Circle

To add a circle area, first locate the coordinates of the center of the circle:

337, 300

Then specify the radius of the circle:

44 pixels

Now you have enough data to create a clickable circular area:

This is the area that becomes clickable and will send the user to the page coffee.htm:

Image Map and JavaScript

A clickable area does not have to be a link to another page, it can also trigger a JavaScript function.

Add a click event on the <area> element to execute a JavaScript function:

Chapter Summary

• Use the HTML <map> element to define an image-map
• Use the HTML <area> element to define the clickable areas in the image-map
• Use the HTML <img>'s element usemap attribute to point to an image-map