A canonical link element helps the webmaster’s in preventing duplicate content related issues.It does this by specifying the “canonical URL”, the “preferred” version of a web page – the original source.
There may be content or even products which can be seen on various different URL’s or on different websites and pages. The main purpose of canonical link elements is that they help you in having all these URL’s without any harm on your SEO rankings.
What is this Rel Canonical link element?
As mentioned above, the canonical link element is the HTML element which can be used when you have many similar versions of web page. The problem of having duplicate content will be resolved when you use the canonical link element. This article is all about how to make the best use of the canonical link element and how to avoid the mistakes that occur while using this HTML based element.
SEO benefits of using a rel=canonical link element
Choosing a correct canonical URL for every set of similar URLs helps improve the SEO of a site. This is because the search engine gets to know which version is original or canonical, which in turn helps count all the links pointing at all the different versions as links to the canonical version. 301 redirect is the same as that of a canonical link element. But the canonical link element doesn’t redirect like how 301 redirect does.
The beginning of the canonical link element
The canonical link element was first introduced in the year 2009 and in the month of February. Yahoo, Bing, and Google were the first companies to work with this canonical link element. The basic uses of this HTML element are simple and it can be applied to resolve complex problems.
Setting up canonical URLs
Consider two-page versions having the same content on both of them without even a single letter difference. The only difference which is seen is that they are in two separate sections of the site. When they are in two different sections it means that their active menus and background colors have not similar. Other sites have linked up these two versions so that the content alone will be much valuable.
Now the question is that which version should be shown in the results by the search engines? rel=canonical is an element introduced for finding solutions for such questions. This problem arises quite often, especially on e-commerce websites.
For example, we can have a situation where two below URLs have similar content on them:
Anyone page from the two pages you have can be picked by you to be the canonical version. If you think that version is the most important between the two then only you pick that particular version. You don’t understand which one to choose among the two of them, then go for the version which has more number of visitors and the most amount of link than the other one. Remember that you should choose any one version for sure.
Now add rel=canonical to the canonical page from the non-canonical one. If you have picked the URL which is the shortest then the other one will link to the shorter one in the head tag part of the page. From the search engines point of view, it merges both of them into one. This is known as soft redirect without redirecting the user.
Which one is better: canonical or 301 redirect?
Unless and until there are technical issues, you can always do the 301 redirects. Only use the canonical redirect when you are not being able to redirect.
Self-referencing canonical URL:
As mentioned in the above example, a non-canonical page will be linked with a canonical version. But the question is should a page set self-referencing canonical URL for itself? Having a canonical link element on each and every page is a good idea as Google also feels that’s the best option available.
That’s because most CMS’s will allow URL parameters without changing the content. So all of these URLs would show the same content:
Thus, If you don’t have a self-referring canonical link element, your page is at high risk. Also, another reason is if you don’t duplicate the content on different URLs on your own there is a chance that someone else could do it to you and lead to duplicate content issue. That’s the reason it’s very good to use self-referencing canonical URLs all over the page. By adding this, it will act as a defense system to your site.
A Digital Marketing Coach and Consultant, having 9+ years of experience in User Experience Design, Web & Mobile Product Management.