Search engines hate duplicated content. Google, reputedly, has a “good cop who just watched his partner get gunned down by the local mob boss at his own daughter’s wedding when he was just two days off retirement” level of hatred for duplicate content.
Eliminating duplicates applies to:
- Page titles
- Meta titles
- Meta descriptions
- Page content
Think about it this way:
- Every page on your website must have a singular purpose/topic it addresses.
- Every page should be the best page on that topic.
If you’re able to tick checks 1 and 2 for each and every page on your website, duplication should be at an absolute minimum.
If you have two or more pages that address the same topic – combine them into one, really great, page. Users, and search engines, will love you for it.
Handling duplicate content with canonical tags
Sometimes, eliminating duplicate content is not as easy as we would like it to be.
This is often the case when trying to optimise eCommerce websites where there are multiple versions of the same product, perhaps with only small (but important) differences between them.
Thankfully, there is a technical solution to this problem – the canonical tag.
The canonical tag allows you to specify that a given page on a website is not the original (or “canon”) version of that page’s content and that another page should be indexed in its stead. The benefits of any links pointing to the page should be passed on, in whole or in part, to the page that is the true original (“canonical”) version.
Doing this can reduce duplication in the search index and promotes the importance of the original page.
However, a word of caution… the pages that are canonicalised to another page disappear from the index.
Canonicalisation Example 1: Good canonicalisation
At widgets.com we used to sell the Widget A1. Now, we’ve released the Widget B1. There’s not a huge difference between A1 and B1.
We want anyone searching for a widget with the properties of Widget B1 to find it, and not to find Widget A1. We suspect A1 is stealing some of B1’s thunder, but we don’t want to remove it from our website because existing users may want to access some of the documentation etc. for the A1.
By setting the canonical URL of widget A1 to point to widget B1, we make B1 the default page. Any links pointing to the A1 page now pass their link-benefits onto B1 and any search engine index results for A1 will be redirected to B1. However, customers can see still A1 on our website and find it by navigating to it from our homepage.
Canonicalisation Example 2: Bad canonicalisation
At widgets.com we make the Widget C10. We also make the C11, C12, and C13. They are quite similar but there are key differences. Our widgets are well known in the industry (of widgets) and people will often search for them by name (e.g. “Widget C12”).
The widgets sell for different prices and our eCommerce platform holds each as its own page. All of the pages are indexed at the moment, but our SEO consultant is telling us we have duplicate content and some of them need to go.
Is this a good case of canonicalisation? No.
If we canonicalise C11, C12, and C13 to C10 we would effectively remove these from the search index. Finding them independently would be impossible.