If you’ve been doing SEO for a while, you know that having duplicate content pages on your website is a no-go. So what do you do when it shows up uninvited? And how did it get on your website in the first place?
Unexpected duplicate pages are actually fairly common in E-Commerce websites, as the same product may appear in different pages (and hence URL addresses) due to categorisation. That is, the product fits more than one category you have on your website.
For example, if your product is a ‘car xyz’, it may appear on the following pages:
Page 1: http://www.example.com.au/vehicle/cars/car-xyz.html
Page 2: http://www.example.com.au/color/blue/car-xyz.html
Page 3: http://www.example.com.au/fast-cars/car-xyz.html
Page 4: http://www.example.com.au/car-xyz.html
Having the same content appearing in multiple pages will confuse any search engine that comes to call. It may even lead to your hard-won ranking results being as duplicated content. So what’s a webmaster to do?
The ideal fix in this scenario is to tell the search engine to regard only one of these pages as the correct result to return when someone makes a search for ‘car xyz’. This is where the power of the canonical attribute comes in.
Now when I say canonical, I’m not talking about the camera brand, or the gun-powder-powered middle-age artillery. The word canonical is an adjective derived from the Greek word canon, meaning ‘rule’. In the internet world, a canonical page is the ‘preferred’ version of a set of pages with highly similar content. This is done by adding a piece of code known as the rel=”canonical” attribute on the ’non-preferred’ versions of the page. This piece of code tells the search engines to effectively disregard the content on these pages – they are exceptions to the duplicate content rule.
For example, in Page 1:
We add the code:
<link rel=”canonical” href=”http://www.example.com.au/car-xyz.html“>
When we repeat this across all the non-preferred pages, we are essentially telling the search engine, “out of all these identical pages, page 4 is the most useful. Please prioritise this in your search engine results”. This way, when someone searches for ‘car xyz’, when it comes to our website, the search engine will point them towards page 4. The search engine is also happy that it no longer has to deal with being confused by pages 1, 2 and 3, so it will not penalise your website for duplicate content.
If you would like to know more about the wonderful world of canonical pages, please watch the video below of Google’s Matt Cutts talking on the subject: