One of the main problems with the Internet today is the amount of duplicate content. This poses problems for searchers who only want to see one version displayed in the search results. It causes problems for the search engines who do their best to index the original version. And finally it causes problems for Search Engine Optimisation (SEO) as site owners are concerned that if the search engines find multiple versions of a page their link credit will be worth less and as a result they will slide down the Search Engine rankings.

The top three Search Engines; Google, Yahoo, and Microsoft, have united in offering a way to avoid duplicate content clogging up the Search Engines and in doing so hope to make things easier for everyone. The solution lies in the “canonical tag”.

The Problem

Multiple URLs for a single page can occur for different reasons but one of the main reasons is URL refer tracking. Adding tracking codes to URLs for the purpose of analysing site traffic produces multiple URLs for a single page and as a result the search engines are likely to index each URL and rank them as separate content, however, only one URL should be indexed i.e. the original or “canonical” URL. With multiple URLs indexed for a single page search engines may crawl the same page three times instead of once. This could result in the robots spending their time crawling duplicate content whilst missing other good unique pages within your site.

Rankings can suffer as a result of duplicate content because whilst the majority of incoming links may point to the original URL there may be links pointing to an URL with a tracking parameter. As the search engines might filter out the duplicate URLs with fewer links you may only get the benefit of all of the links to your site that you deserve. Consequently whilst your site should be appearing third in the rankings for a search term it may drop off the first page completely. All because of duplicate content. Youtube and social media sites have only fuelled this problem but now there is a solution.

The Cononical Tag

To specify the original, or “canonical” version of the URL merely use the following tag within the head section of your page:

<link rel=”canonical” href=…

This will result in the links to all the multiple URLs for that page being consolidated, resulting in you receiving the link credit and the search engine rankings you deserve.

Posted In:

Google, Link Building, Search Engine Optimisation