Canonicalisation scares

WHAT? Recently, we've seen SEO companies using a soft-sell scare tactic to try and get business by telling web owners there is a canonical issue with their website that is reducing its search ranking effectiveness.

Let's first understand what a canonicalisation is and why it is unlikely there is a problem with your site.

URL canonicalisation, despite being difficult to say is quite easy to understand. Basically, it is the process of arriving at the definitive URL address of a webpage. Take a look at these two URLs:

• www.blotdesign.com/about-us.php
• blotdesign.com/about-us.php

Although these two addresses look similar and will normally take you to the same page, in strict web terms they are actually two different addresses. If you used both these addresses all over your website, Google would wonder which one was the definitive one.

The theory goes that if it chose one, you would miss out on the Google juice for the other. In experiments we have done, we don't believe that to be the case but whatever, let's assume that this did happen. What do you do to stop it happening?

Pick what you want to be the definitive url (www or non-www) and make sure that all links use that reference.

Done that?

Potential problem is gone.

Most web development companies would build their sites like that anyway so most of the time it is a non-issue. If you've done this you really don't have to do anything else but if you're really concerned, here are a few more things you could do:

• You can add a rel='canonical' statement to the page which states what the definitive url should be
• You could add a 301 redirect so all non-www addresses are automatically redirected to www addresses.
• We've also seen home page references such as www.domainname.com/index.php redirected to www.domainname.com because someone thinks that the ranking juice is going to be divided between the domain name and the name of the home page.

But none of these are really necessary, so long as your links are definitive and consistent.