What the Heck is Canonicalization and What Does It Mean to Me?

“Canonicalization” refers to a computer science discipline that converts data (which has more than one possible representation) into canonical form, which essentially means, a normal form.  However, SEO canonicalization refers to URL canonicalization.  This is the process of making URL addresses (which each Internet page requires) into a “normal” or standard format.

More to the point, canonicalization is the process of choosing the best URL when there are actually multiple choices that could be returned, and all within the same site.  For example, let’s say you created a domain called YourSite.com.  Now what if there are searchable pages of YourSite.com, as well as www.YourSite.com, and www. YourSite.com/index.html and YourSite.com/home.asp?  That’s actually four different URLs, even though it’s the same website and content.  Thus, canonicalization is simply the process of choosing the best URL for the search.

The goal is to convert the multiple URL into one canonical (or standardized) URL.  Major search engines already use URL normalization techniques so that they can assign importance to certain web pages and to reduce indexing of duplicate pages.  The process also makes web crawlers stop crawling the same resource over and over again.  The process can also determine what links have been visited or cached.

You can pay an SEO writing firm to take care of this for you, or attempt to go through your web page and point all links to one unanimous page, as in www. or no www. throughout the site.  Try to stick with the same standard all over your site.  (This is why working with CMS helps!)

You can also redirect traffic to a specific page by setting a default URL.  The correct code is a 301 (permanent) redirect, which basically spells out to search engines how you want canonicalization to be configured.  Whatever you do, do not use the URL removal tool!  This could totally delete your website or domain for months.  You can also use sitemaps to correctly identify the right canonicalization.

The important thing is that duplicate pages are stopped from displaying, as this is a violation of search engine policy (unless there is clear evidence of re-publishing and by the same author).  Besides, another reason to invest in canonicalization is to solidify your link building stats, since spreading the traffic around to different URLs minimizes your overall traffic.

Last but not least, don’t worry too much about moved pages, since search crawlers will eventually find them missing and update their indexes.  Canonicalization is not difficult…it’s just a matter of correct mailing!