AJAX, along with Flash the ugly kid of web development for SEO, was introduced in 2005. The expectations were high but it never really got popular. A survey in October 2008 reported that 3.20% of the web pages tested used the XMLHttpRequest DOM object, an important part of AJAX.
The combination of AJAX and SEO has never been a good one. SEO has a strong fundamental basis in the document structure of the web. AJAX creates possibilities to discard the document structure of the web and offers a way to create single page websites. Gmail for example is a single page website.
AJAX and SEO seem like two worlds which cannot be united, or can they? While extensive use of AJAX should be a threat to SEO it doesn’t get that much attention. A search for ‘AJAX SEO’ in Google returns mainly articles dating from 2006, 2007 and 2008. Time for a little update.
On the other hand AJAX may offer some possibilities for SEO. There might be information you want to show to your users, but not so much to the search engines. This is where AJAX can be used in your advantage for SEO.
For example, when you have a product page with the basic information about a product (/product/). You might want to show the user a page with the specifications of that product as well. You could create another page with the product specifications (/product/specs/). However search engines will be able to index this page and this page will gather value next to your original product page. Now you have two pages optimized for the same product. Imagine if you have even more pages with information about this product.
Instead you could update the content of the product page with the specifications of the page through an AJAX request (/products#specs). This way you can show extra product information without creating an extra page. And best of all: with the use of the # in the URL users can link directly to the specifications but the link value for search engines will go to the original product page you want to rank for.
Other actions you could complete with AJAX (in order not to produce new pages you don’t want to be indexed) are:
The limitations of AJAX for SEO has been asking to be solved for a long time. The problem with making AJAX crawlable is that all the content not meant for indexation could be indexed all of a sudden. The fact is however that search engines are working on a way to make AJAX crawlable. Google, as an innovator in improving the web, sees the benefits of AJAX and has been using it already for a long time. Gmail as well as Google Wave and Google Maps thrive on the possibilities and the speed of AJAX for the usability of its interfaces. Google even developed a web toolkit for development of AJAX applications. Therefore they also wrote a guide on how to make AJAX applications crawlable. The way search engines want to make AJAX crawlable will not interfere with the way AJAX is used now, but it offers a way to make certain specified information crawlable and regular AJAX applications not. In March of this year Google officially announced that they started crawling AJAX. And the first results are already here: