Canonical Tag: What it is, how it works and when to use it

Canonical Tag
Canonical Tag

The Search for the Top of Google, Bing, Yahoo! And so many other search engines is the main goal of most businesses present on the internet. And the reason is very simple: Reaching new customers from these pages, free and organic, directly impacts the number of sales. But being […]

The Search for the Top of Google, Bing, Yahoo! And so many other search engines is the main goal of most businesses present on the internet. And the reason is very simple: Reaching new customers from these pages, free and organic, directly impacts the number of sales.

But being on top is a complex task, reserved for those who understand the importance of investing in content, website optimization and SEO. To make matters worse, with ranking algorithm updates every year, the rules are always changing. Google, for example, updates its algorithm all the time, implementing improvements to provide a better service.

This way it is critical that you recognize what is important for your site to rank well. Among the main techniques is canonical TAG, a subject we will explore in the following paragraphs. Keep up.

What is canonical TAG

Considered the biggest revolution since the implementation of sitemaps, canonical tag appeared in search engines in 2009 and since then basically serves to prevent duplicate content from being indexed by algorithms.

Search algorithms don’t like duplicate content because they trick the engine into thinking that the site has more traffic and relevance than reality. This is very common in forums, websites with mobile versions or pages with print versions. Pointing to Google or any other search engine that many of your pages contain identical content and referencing the source page is called “canonicality”.

The canonical TAG’s function, in this context, is to mark the algorithms’ understanding that that page is a replica of another and not index it in the same way.

How does it work

In essence, you use canonical TAG like a 301 redirect, where you tell the algorithm to go to another page. However, canonical TAG works only for search engines, allowing you to bring visitors to that page.

Following the example we mentioned earlier, of printable pages: with canonical TAG you do not allow that page to be indexed, but allow the user to access it. If you use a 301 redirect, you will not allow access from either.

This way, canonical TAG works as a way to optimize your SEO without harming your visitors’ user experience.

Where, when and how to use it

When search engines don’t identify which version of your content needs to be included or excluded from indexing, or when they don’t know which page to guide metrics for trust and authority, they often reduce their ranking relevance.

Therefore, you should use canonical TAG each time your site creates multiple versions of the same content, such as print pages or even pages where only a few URL parameters are changed.

For example:

Your main page can be accessed by a few different URLs, such as:

  • www . my company. with
  • my company. with
  • www . my company . with /
  • my company . com/index
  • www . my company . com/index
  • my company. with / home .aspx

Each of these will represent duplicate content (as they will all have the same page). However, by using the canonical tag, you will prevent search engines from seeing them as duplicate content and passing all authority and recognition to a single link.

Canonical Tag Example

Canonical tag: its application in practice

First is defined the canonical domain, ie, the search site (Google, Bing, Yahoo…) will be informed that a particular URL will be the preferred page indexing to your site, remembering that you must choose between the version with or without www, and then, when indexed, this domain will be used for search results as well as for future page crawls and updates.

Its application is quite simple, just use the references “rel” and “href”. Let’s say the preferred URL is “” so that this is intended for search engine robots, you must add an <link> element to the head section of the pages. www. my company. com / institutional”, so for this to be suitable for search engine robots, you must add an <link> element to the

<link rel = ”canonical” href = ”” />

When this activation occurs, it is certain that most users will come across this URL every search result the page appears.

Application on pages providing documents

Suppose one page of your site provides an ebook in the PDF format called “Weekly Magazine Ed.1”; you will need to add a canonical URL so there are no duplicates and the document can be accessed through multiple addresses.

For the preferred link to be “ ”, the procedure will be as follows:

Link = <>; rel = ”canonical”Http : // www . my company . com / downloads / magazine – weekly – 1 >; rel = ”canonical”

The importance of using Redirect 301

This practice will ensure that traffic, as well as search engines themselves, is directed to the correct destination. Code 301 will make these engines understand that the page has been moved elsewhere, rather than detecting it as duplicate pages.

It is also recommended to use 301 redirects when aiming to redirect visitors from one domain to another, which can happen when a company changes its name and, with the intention of preserving its customers and followers as much as possible, seeks to do so. get used to the changes instead of migrating completely.

In this case, you need to make sure that each of the old URLs leads to the new domain on the respective pages where each ‘new version’ of the content is located. Some other important points should be taken into consideration:

  • Always keep Google informed of changes. That is, if you migrate to a new domain, you can change your address in your site settings through Google Webmaster Tools.
  • Make sure the new domain is tracked by Googlebot.
  • Make sure your old URLs are not blocked, as they will prevent redirection.
  • Be aware if visitors are encountering error 404, although it is best to prevent the problem from occurring. One tip we have to help with this task is that you do the testing yourself, making a list of all URLs and accessing them through Quick URL Opener. When detecting URLs that have an error, try to fix the problem as soon as possible!

Canonical URLs on social networks

It’s good to clarify a peculiarity of social networks when using “rel = canonical”: when a Twitter or Facebook URL is shared, and a ‘like’ button is added, the likes count will only be displayed in the canonical URL, or that is, if the user is at any URL that references a canonical, the user action will not be enabled on the current page.

Some common mistakes to avoid

When canonical tags begin to be applied by the inexperienced, it is very easy to fall into a series of misconceptions that can completely destroy traffic. Therefore, it is essential to obtain as much information as possible before acting, preferably following the recommendations of the search engines themselves that adhere to these tags or true subject matter experts, in this case, experienced Webmasters.

But to prevent you from taking any risks, check out a few errors that can be avoided early on, ensuring a good experience with canonical tags early on.

1. Don’t understand that canonical tags exist for one purpose only.

Much of the trouble beginners experience is that they overlook one big detail: the strategy is only to avoid duplicate content and nothing more!

With that in mind, avoid applying canonical tags for any purpose other than to troubleshoot duplicate content, as the chances of generating new problems are very high.

2. Apply rel = canonical to wrong locations

For the technique to work, rel = canonical must be located in the <head> section, otherwise, when code is inserted into the <body> section, search engines simply ignore the reference. In addition to rendering the technique unusable, this can compromise the page’s HTML structure.

3. Do not check source code carefully

More common than creating code templates ready to declare rel = canonical for the sake of speeding up the work, it is even more common to copy it without making any changes to the destination link. It’s like redirecting the user to the wrong page, putting the reputation of the site as a whole in check.

The use of SEO plugins can also lead to issues of the same nature, such as the inclusion of two or more canonical statements in the same source code, and just as in cases where the referral is outside the head section, search engines too. will ignore your application.

4. Use canonical tags on non-duplicate pages

As explained in the first common mistake, the technique should only be applied to duplicate content. An example that is becoming classic is the use of canonical in articles that extend to other pages, making all pages refer to the first.

Thus, all the content of the pages after the first one will be lost precisely because it is not duplicate. In this case, it is recommended to use a canonical tag to have a full view of all content (all pages).

What did you think of our article? Did you like the topic and want to go deeper to apply it to your site? For this we recommend you visit our 15 valuable tips for creating well-structured URLs. Enjoy the content well, after all, we made them thinking of you!

Optimizing your page to rank better with Google will surely become one of your company’s top marketing channels. Thus, it is critical that you are up to date on SEO best practices. If you have questions or do not know how to use canonical Tags, please contact our team from the comments below. We can help you!

Scroll to Top