Canonical URLs: What Are They And Why Are They Important In SEO?

what is canonical URLs and why is it important

We’ve been sharing a host of well-known SEO tricks with you in our blogs- what to do and how to do it right.

Today, we’ve come up with a lesser-known SEO hack that is not fully utilized by most people! In fact, many may not even know about it!

Have you ever checked if you have duplicate content on your website? Or if you have published the same content on multiple websites? Do check and give this is a good read.

Because we have disturbing news! Google often keeps duplicate content off the high rankings because it is too confused on which version to rank. Woah!

But you shared it on 5 websites for more reach! What should you do now? Calm down and give this article a good read.

We’re spilling the tea on how to maintain duplicate content and yet have your website shoot to the top of Google SERPs!

What is a canonical URL?

When you’ve been creating content on a website for a long time (say 3 years and more), there’s a good chance that a few web pages may start seeming quite similar to each other. Multiple articles which are marginally different or different blog posts which are targeting a rank for the same keyword.

In such cases, it becomes confusing for the search engine to decide which page it should index and rank. Since it is essential that we give the users the best version of the content, we should point Google (or the other search engines) to our preferred version of the article. Because let’s face it, it wouldn’t be too wise to let Google make the decision on its own!

Canonical URLs help exactly in this situation. They help clearly point out to the search engine which version of the content we want users to read.

What is the use of a canonical URL?

A canonical URL is used to show the search engine which version of certain content is the original or preferred version.

It is particularly useful in cases like guest-blogging or A/B testing your web pages. In the first case, you would like the search engine to know that your website has the original version of the blog post, even though you have allowed another publication to post it on theirs.

It is a usual practice by e-commerce companies, where they use canonical URLs to show search engines the original content on the client website. This helps them maintain a high level of trust with the client.

When to use a canonical URL?

There are many situations in which you may have to use a canonical URL. Below I am listing a few significant reasons websites use canonical URLs

1. In case of syndicate blog content

Content syndication is a good way to build reach, brand and links. However, in this case, your content is distributed across multiple domains and Google has a tough time figuring out which one it should go for.

Since your ideal aim is to drive readers to your own website, you should use canonical URLs in your web page to point to the original post on your site.

2. To repost existing content on a partner website

If you are partnering with a more prominent website or are a section of a larger organization, you may have a separate website to promote their content. In these cases, it is better not to leave it to readers to follow a link back to the original website.

Canonical URLs can solve this simple issue by telling the search engines which page holds the original version of the content.

3. While A/B testing web pages

A/B testing web pages is a superb practice! You test the color, infographics and other parameters to see which one the audience warms up to the most. However, in this case also, Google is at a loss to decide which one it should index and rank and end up not ranking either!


So it’s better to tell Google that “This here, is what I want you to treat as the preferred version of the content. Please ignore the other one!”

4. Parameterized URLs and URL Variations

This point is especially crucial for e-commerce websites. The URL changes with the hierarchy of the product.

For example, if you initially search for Women’s Apparel under Fashion on Amazon. Then you move to polo tees under that category.

Here, though the page is the same, the URL is not. So now, your website has 2 URLs with the same content.

With your canonical tag, you can redirect Google to rank only the page with top hierarchy, that is Fashion.

5. URLs with uppercase letters

Search engines are case-sensitive - they treat uppercase and lowercase letters as totally different things. As a result “” and “” are not the same to them.

So you can either stop using uppercase letters throughout your site or use the rel=”canonical” tag.

6. Pages created for separate devices

Google may end up indexing the same page created separately for different devices as different pages having unique content.

rel=”canonical” is the simple solution to that!

7. Printable version of the page

Printable and non-printable versions of the page have the exact same content, right down to the T. But. Google sees the extra “printable” tag on one of the URLs and deems it different.


It’s on you to clear the confusion - so go ahead and add the rel=canonical tag on the original version of the page!

8. Different variations of the same page

For the search engines, HTTPS and non-HTTPS URLs are totally different. Even if the content they carry are carbon copies of one another. Using canonical URLs in this case saves time and helps you rank quicker.

What does a canonical URL look like?

The canonical URL is more often than not found in the header of the page in Source. So go to the Source and look for rel=”canonical”. A canonicalized URL generally looks like this:

< link rel=”canonical” href=””

Different Ways to canonicalize multiple URLs

Even though adding the rel=”canonical” tag in your header is the most common and most preferred method, there are quite a few other ways to go about canonicalizing your URL. Read ahead to grab the different tricks!

1. Add rel=”canonical” tag in HTML header of page

This is by far the safest and most recommended method of using canonical URLs. Just add it to the header of the duplicate page!

If you have a WordPress website, just use the Yoast plug-in. It takes care of canonical URLs all by itself!

Even Shopify adds self-referencing URLs to catch this issue beforehand.

2. HTTP header

This is a life-saver for PDFs posted on different sites and pages. You can add the tag to the HTTP header to indicate which one is the original post.

It looks like the code below:


However, Google does not allow this for images.

3. Sitemap

This ones easy to do and doesn’t require you to add tags on a hundred different pages. Simply list only the canonical pages in your sitemap.

Since Google automatically takes those to have more precedence than the other pages, your job is done and in far less time!

4. Internal Links

When you link one page on your site to another within the site, you’re practically signaling to Google that this page is important and I prefer people to read this.

And Google being as smart as it is, quickly takes the hint!

5. 301 redirect

A permanent redirect to another webpage.  This is a sure-shot way of indicating to Google that you want it to ignore the page and move to the other one as you prefer that for users to read.

6. Passive parameters in Google Search Console

Just hit the console and type in the URLs you want Google to overlook completely. And that’s what Google will do

7. Location Hash (#)

In case two pages on your site have a very small, specific difference, you can use a location hash to send the search engine to that specific area which has the change. Then the search engine will no longer adjudge them as different pages.

Best practices to integrate canonical URLs

  • Use absolute URLs and not relative paths when you put in the rel-”canonical” tag.
  • Throughout your website, use only lowercase letters, so as not to confuse Google any further regarding which URL is canonical.
  • Always use the correct domain version (http/https or www/non-www)
  • Self-referential canonical tags- that is, the page pointing to itself as canonical. So Google need not look any further.

Why are canonical tags important for SEO?

Canonical tags are critical for better SEO. In case you have duplicate content on your website or content that you’ve published on multiple websites, Google gets all confused about what to do.

It can’t pinpoint which one to rank or index, and this may end up harming your ranking and domain authority.

The three specific areas in which canonical URLs boost SEO are:

  1. They signal to Google which version to rank
  2. These URLs make Google’s job easier by choosing which site Google should rank for keyword queries.
  3. Google can then decide if only one of the sites gets the link equity or if it should be split.
  4. Make sure Google doesn’t waste time on duplicate content on your page, but rather it crawls the more important content.

Case Study

Let’s say you’re waiting to snag that Adidas sneakers in size 37 during a sale on

Now the sneaker is available in three colors- red, blue and black. Though it’s the same make, material and maybe even price, the sneakers will have separate URLs based on color.


But the content is absolutely the same on two pages! It is here that the canonical tag comes in VERY handy. Simply add a canonical tag for the top page having the Adidas sneakers as the canonical URL. And Google will rank that page for you.

So that next time, when you search for the same product, you get to again view all the sub-categories together.


Though it was earlier thought that Google penalizes duplicate content, of late it has been found to be just a rumor. Google doesn’t punish you for having duplicate content.

But, it may completely overlook both your pages out of pure confusion. And that puts you out of the good rankings and thus, the whole purpose of having compelling content on your website is lost.

So, it is imperative that you find your duplicate content and use the canonical URLs. Make sure you really need to use it and you are implementing it in one of the ways mentioned above.

After protecting your brand and website, you can go ahead and publish as many guest blogs as you like to increase your reach and awareness.

People get to read your work AND your website retains the rankings.

Win-win situation.


The SEO game is a toughie as it is! Why would you want to mess up your chances with unintentional mistakes like duplicate content? And that is why canonical URLs are a must! To make sure you’re on top of the game.

If you’re not very sure of how it works, you can always hit us up! We’ll spruce up your SEO game and make sure you never fall out of Page 1!

‍Marketing Team