What is a Canonical URL?

A canonical page is the preferred version of a set of pages with highly similar content. It’s common for a site to have several pages listing the same set of products. In other words, a canonical URL is the URL that you want visitors to see.

Quite often canonical URLs were used to describe the homepage. The typical example used is that most people treat the following URLs as the same:

1)www.example.com

2)example.com/

3)www.example.com/index.html

4)example.com/home.asp

But technically all of these URLs are different. A web server could return completely different content for all the URLs above. When Google “canonicalizes” a URL, we try to pick the URL that seems like the best representative from that set.

So how do I make sure that Google picks the URL that I want?

One thing that helps is to pick the URL that you want and use that primary URL, or as we will call it, the canonical URL. Then, in all the other pages that are identical, you can use the canonical tag to inform the search engine about the URL of the original (canonical) version of the page. This eliminates the so-called duplicate-content penalty.

Implementing the Rel=”Canonical” Tag

One of the easiest ways to implement the canonical tag is to include a “Link” directive inside the “Head” section of a webpage. Assuming that you wanted to indicate that

is the original URL, you would place the following:

<link rel=”canonical” href=”http://www.EcommerceWebsite.com/Disney-Products/Umbrellas/Green-Mickey-Mouse-Umbrella/”>

In the Head section, i.e., between the tags

Place the rel=”canonical” declaration on all the pages which are similar to the canonical page. In fact, it might be a good idea to place the canonical tag on the original page itself. When that page is called with search parameters or session ids, the canonical tag indicates the original version of the page to search engines, thereby completely eliminating this type of duplicate content problem from your website.

Canonical simply means relating to or belonging. It also means reduced to the simplest and most significant form. Just remember that a canonical URL is the simplest and most significant (authoritative) version of the URL that you want to be seen.