How to tell if a site is using Ajax and why you should care

From an SEO perspective, you need to understand how a site operates in order to better optimise it for the search engine crawlers. Ajax generated contents online are largely not indexed by the search engines, and although this is likely to change in the future, the use of Ajax to generate content that is intended to be indexed by the search engines is not recommended at present − a classic example of search engines holding back progress of the web.

In most cases you would be able to get a good idea if a site is using Ajax by observing the visual clues often associated with Ajax based operations such as the display of an “operation in progress” icons to indicate an Ajax based operation is in progress and the lack of the usual page refresh while processing a requests. But none of these visual clues are reliable enough as some seemly Ajax based operations might turn out to be fancy dynamic HTML JavaScript effects. It is also common for Ajax based operations not to give any visual clues all together making it hard to spot.

To find out for sure if a specific operation on a page is Ajax driven, you would need to observe the “XML Http Request” being sent to the server while running the operation in question. The “XML Http Request” is the protocol used to send Ajax requests to the server and so the presence of such a request indicates an Ajax based operation in progress.

There are a number of browser plugins that allow you to monitor XML Http Requests sent by the browser. I personally use the Firebug plugin for Firefox which is a very useful tool. Once installed Firebug displays a Bug-like icon at the bottom right corner of the browser window. Clicking on the bug-like icon launches Firebug as shown in the image above. Select the “Net” and then “XHR” to launch the XHR console where all XML HTTP Requests sent by the browser will be displayed. In some cases you might have to enable the “Net” tab for this to work by clicking on the drop down arrow beside it and selecting enable.

With the XHR console opened, run the suspected Ajax based operation and monitor the console for any requests being sent which indicates the operation to be Ajax driven. Note that the XHR console only shows Xml Http Requests.

In this case I have used the Firebug plugin with Firefox; however, you should be able to find a similar plugin to use with your favourite browser too. I hope you find this useful and insightful.