What is Canonicalization
In terms of SEO, canonical has a generic meaning of making an object – in this case a URL – conform to a rule that is the standard or usual state.
A canonical form of a group of objects in the digital format can capture the essential characteristics of that group in a very specific fashion. Canonicalization of a URL means that you have a standard way of showing your website address every time it is used. For example, consider the following four URLs:
Essentially, many would consider these the same URLs; however, all could return a completely different page. A part of the issue of canonicalization is ensuring search engines find the best page for the search. To help make this happen more efficiently is to be completely consistent in your linking on your site.
Choose which URL fits your needs best, and consistently use that format every time you make an internal link. Another tool for ensuring search engines know what is the favoured URL is to set up a permanent 301 redirect to your chosen URL from all of the other possible URLs such as those listed above. By doing this you are confirming which one is the primary canonical URL.
Why is using canonical URLs important?
Simplistically, for a great user experience and SEO results, if quality content is King, then backlinks are Queen. The more backlinks your site has, the better opportunity your users have of finding you. Your ranking in Google searches increases with more and better backlinks.
Consider you have only one URL which every single link from other sites links to; if you have a second URL which gathers links and half go to the first URL and half to the second, you dilute your backlinks by separating them to different URLs. This means you would only benefit from half the backlink kudos when a user searches for you in Google, thus, reducing your place in the rankings on the search page. Imagine how you would dilute your backlinks if you had 4 or 6 possible versions of your URL out in the WWW.
5 Steps to having helpful canonicalization in your business
Determine your preferred URL
Ensure all of your internal linking is using the same preferred URL
Create or fix all 301 redirections from your other URL names to the correct single URL
Make sure you have a XML Sitemap. Your Sitemap will show Google which address you want as the canonical address for your site
When you initiate links to your site, ask nicely and spell out exactly what URL you want your prospect to link to, don’t take it for granted they will guess!