As of January, 2012, this site is no longer being updated, due to work and health issues

Testing Search Indexing Robots

Links in Image Maps

This page is testing whether search indexing robots index links in image maps. For more tests, see the List of Robot Tests.

Image maps are graphic images with links or actions associated with sections of the image. For example, a map have different links when you click on California, Illinois or Maine. There are two kinds of image maps defined for HTML (see the HTML 4 specification for Image Maps for details).

Client-Side Image Maps

These are HTML commands associated with an image which include links, triggered in the browser when a user clicks on a particular point on the image. Most robot spiders can follow links in these formats, because they include the familiar HREF codes.

Here is a simple image with client-side image map codes:

circle rectangle

The associated map commands look like this:

<map name="client-side-map">
<area shape="circle" coords="91,49,38" href="client-map-circle.html">
<area shape="rect" coords="180,19,293,78" href="client-map-rect.html"> </map>

To test whether a search indexing robot follows client-side image map links, search for Client Image Link Circle and Client Image Link Rectangle (without the spaces). If you find the page, the indexing robot can follow those links, otherwise, it cannot.

Server-Side Image Maps

server-side maps, which store their links on the server and wait for the user to click on a particular location in the image before serving the link. For a good explanation, see the Webmonkey Server-Side ImageMap page.

Robots can't click on the map, so they are stuck. To serve robots (and non-graphic browsers), any site with server-side image maps should also have text links on the map pages, or a link to a page that lists all the image map links.

In this example, the graphic has a link to a very simple image map file:

In the image map file, the commands are quite similar:

# Format: NCSA 

  default server-map-background.html

  rect server-map-oval.html 193,15 270,87 

  rect server-map-rect.html 27,18 140,76 

The server will translate all clicks in the stated coordinates of the image files into the appropriate URLs, so a click at the upper left corner (1,1) would link to the server-map-background page.

While it is possible for a robot to send all possible combinations of coordinates to the server and follow all unique links that it gets back, it's highly unlikely that any would do so. However, in the spirit of enquiry and exhausive research, we have set up a test. Search for Server Image Link Oval and Server Image Link Rectangle (without the spaces). If you find the page, the indexing robot can follow those links, otherwise, it cannot.