Canonicalization: What Is it? How Does it Impact Me?

We recently had someone make contact with us who wanted us to do a website review on their site. Unfortunately, they had an issue called canonicalization where search engine saw their website as being 4 different sites!

What Does Canonicalization Mean?

Canonicalization means that search engines see multiple versions of your website. The most common is that a search engine will see two versions of your website. For example:


It may not seem like much of a problem but this is not great for several reasons.

Having different versions of your site means you lose link authority if someone links to your site. Imagine you had three visitors come to your website and link to it.

Visitor 1 links to your site as Visitor 2 links to your site as and visitor 3 links as

What it means is that when the Google spiders start crawling on these links, they see them as three different pages. Each link is like a vote so each “different page” gets one vote.

The more votes your page gets, the more authority it has. Having these votes split into different pages means that your authority is diluted. Your website would be in a much stronger position if it had 3 votes to the one page instead of 1 vote to each page. This of course is amplified the more links you get to your website.

Duplicate Content

Having the same content on multiple pages also makes it look like you have the same content on your website. Some argue that this is not great from a search engine perspective because it can mislead search engines by making them believe them believe that you are stealing someone else’s content when it actually your own! Some believe you could be penalized for this.

Personally, I think search engines are smart enough to tell the difference if it is coming from the same URL, however one could argue that a non-www version of your site and a www version of your site is different URL. If getting to page 1 of Google is your objective, I would play it safe and just get the issue fixed.

You can set your preferred domain in Webmaster Tools or ask your friendly website designer to help resolve the issue at the server level. Either way, there is a simple fix.

This is a Common Issue

We recently attended a networking breakfast in Brighton and grabbed the business cards of 24 members. A quick look through Google to do a canonicalization analysis on the group members and I discovered that 65% of the websites from that group had an issue with canonicalization. Only 15% didn’t have this issue. The rest either didn’t have a website or their website was down.