How To Check For Sub-domain Duplicate Content Which May Lower Your Google Rankings

After Panda and Penguin updates, it has become absolutely important to prune duplicate content and other leakages in our sites to make them absolutely compliant with Google's Webmaster guidelines. We will be discussing some of the issues which webmasters ignore but are important to follow in the eyes of Google in the later articles. The focus of this article will be the sub-domain duplicate content which can be caused unknowingly but can be lethal if Google penalizes the site.



Although Google Webmaster guidelines state that we should not use noindex or nofollow for internal pages of the site, Matt Cutts advice is a little different. According to Matt Cutts, we should noindex all the pages which we don't want to rank for in Google Search. This includes subpages of the main pages because we usually want to rank for the main page instead of the subpage.

If you are using Wordpress, you should know that Wordpress creates a lot of extra pages which carry duplicate content like categories, tags, date archives, author archives. These pages can be of great value to the reader but need to have some valuable content in addition to the list of posts.

So what exactly is subdomain duplicate content? Actually if we are creating subdomains like mail.itechtics.com, web.itechtics.com and redirecting them to the main www.itechtics.com, they are producing identical content as on the main site. This will lead to duplicate content. You should tell Google which is the original version of the content.

First of all, we will check if there are any indexed pages with subdomains other than www.itechtics.com. To see this, go to Google.com and search for:

site:itechtics.com -www.itechtics.com

Replace itechtics.com with your own domain name. This will show you the possible problematic pages.

So how do we solve this problem? You have to insert the canonical tag on each page which tells Google about the original source of the content. If you are using Wordpress, this problem can be solved by using an SEO plugin like Wordpress SEO or All in One SEO.

Image credit: PiattiLeti