Coding, SEO

Canonicalization: You must solve this canonical issue to avoid Duplicate content

Duplicate content is an issue that can get a penalty to your website. Google always asks to write unique and good content...


Duplicate content is an issue that can get a penalty to your website. Google always asks to write unique and good content to get rid of the panda penalty. There may be many factors in ranking a website in Google SERPs, but alongside that, there are factors that can get you a Google penalty, if avoided. Canonicalization is one of the major factors that can get you a Panda Penalty.

In this post of mine, I will be sharing how you can solve the canonical issue to avoid the Panda penalty or duplicate content issues on your own Website. Canonicalization is a basic On-Page SEO tag that helps the search engines to consider one URL for your Website or blog.


What is Canonicalization (canonical Issue)?

When for the first time I heard the word canonicalization, I was thinking of some other meaning of it. As the word is difficult to speak and spell but it has great weight. Well, let me explain to you the term canonicalization. Many SEO experts and webmasters use the term Canonical issue.

I will try to explain this term and how you can use this term to solve your canonical issue.

Suppose we have two URLs for a blog or a website (like the links below).

  • https://example.com
  • https://www.example.com

If both of the above URLs show the same content and no redirects are allowed on these two URLs. Like “https://example.com” is not redirected to “https://www.example.com” and vice-versa using the canonical tag. This will be considered duplicate content for Google, and the site owner will face the panda penalty for the duplicate content. And solving this canonical issue can be termed canonicalization.

This can even happen with a plane Website without CMS. Which may have an index.php file and the domain name and if this canonical issue is not solved then one can face the penalty for duplicate content from Google or other search engines.

  • https://example.com
  • https://example.com/index.php

If the above of both URLs show the same content, then that will be considered as duplicate content for Google.

Although search engines are becoming good enough and are also using artificial intelligence. But we still need to conform to the search engines which URL they must follow. Actually, search engines use bots that can’t decide whether the URL is from the same page or different. These bots will consider duplicate content if we do not solve the canonical issue.

If the URL of your website appears with both the non-www and www in any of your browsers, then it is for sure that you need to fix this canonical issue. You must fix your server’s settings so that your website URL appears with only one URL so that whether you type the URL of your blog with www or without www in any of your browsers, it redirects to only one URL. You can try my blog’s URL to check this issue. Either you type the URL of my blog with or without the www, but the URL of my blog will automatically be redirected to the “https://www.trickyenough.com/.” So, if you are using both two URLs for your blog or website, then there is an important tag that you can use to let the search engine know which URL they must follow, you simply use rel=” canonical.” And just this simple tag can save you from getting a penalty.


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How to perfectly apply the URL Canonicalization?

For implementing the URL canonicalization perfectly, you need not code long lines. For solving the canonical issue you just need to type a single line of the tag. You can check the below tag for the same.

<link rel=”canonical” href=”https://example.com/index.php”>

Let’s understand with the help of an example: suppose your website or blog has two URLs and both URLs have the same content and you need to show Google that the content belongs to one source only and no content is duplicate or identical to each other.

  • https://example.com/indexp.php
  • https://example.com

Now Google thinks that the above two URLs are different, but you can simply use the tag canonical for the “https://example.com/index.php” to convey to Google that the URL is identical or canonical to the “https://example.com/.” And I am sure that doing this will help Google understand easily that there is no duplicate content on your site and you will be saved from the Google penalty.

Where to use this Canonicalization tag?

This tag must be placed in the header section of your website or blog. The tag will not work if placed somewhere instead of in the header section.  You can check the below image for reference.


In the above image, you can see that I have kept the canonical tag in the header section only. There are two canonical tags for the blog because blogs have multiple pages with posts. Then that tag can be used next to the canonical tag like this:

<link rel=”next” href=”https://example.com/page/2/”/>

How to solve the canonical issue in WordPress:

WordPress is one of the most popular platforms and solving the canonical issue with it is also important and easy. I have worked with many WordPress websites and blogs and believed that you need not put the canonical tag in the header section. You can simply use Some SEO plugins like SEO Yoast and All in One SEO to their work easily.

If you are not familiar with WordPress, then I suggest you first read why to use WordPress for your blog and then a complete guide to starting your own self-hosted WordPress blog.

canonical issue

As in the above image, you can see that you can easily use a URL for your blog and website. Whether you want to go with the www or non-www URL of your blog or website, it’s your will but make sure not to fall victim to duplicate content.

So, after installing WordPress, I suggest you check your general setting in your WordPress and fix the URL if there is any problem.


If the URL in the general setting is the same as it was while installing it, then you can leave the other thing on the SEO plugins. And I am sure that you will not be facing any penalty with your blog or website.

When must you be using Canonicalization?

It is not only important to use a canonicalization tag on the place, but it is also important to decide when you must use it. Because there may be a situation or CMS, or coding when we need not use the canonical tag.

You must solve the canonical issue when in need: below are the conditions given:

  1. When there are two URLs for the same content.
  2. When mobile sites are having the same content on little different URLs.
  3. Having HTTP and HTTPS URLs with the same content.
  4. Also, when categories and tags have the same content.
  5. When the website has non-www and www versions showing the same content.

Suggested post:

Moving your WordPress site from HTTP to HTTPS for free.

Best Copyscape alternatives to check plagiarism.

Other things to be kept in mind while doing canonicalization:

  1. Do not use multiple canonical tags. If your blog or site has multiple canonical tags, then it will be considered a bad SEO practice. Try to use only one canonical tag with clear preferences. I have also written a post on the things that hurt SEO, so I recommend you to read it.
  2. Try not to add canonicalization tag on the second page of your URL as possible that Google may not index the URL. What I meant to say is that Skip pagination canonical Issue. The Sitechecker tool will help you analyze your site and find the problem of multiple canonical URLs. You can also check out a detailed list of tips on how to fix this problem.
  3. Never use the canonical tags on the Links which are shortened. Applying a tag to the shortened URL will end up in many errors. It will be better to use shortened links for Better indexing.
  4. For solving the canonical issue with mobile versions of the website. Google has suggested using the two Rel tags, (rel=” alternate” and rel=” canonical”) which specify that the URL of the mobile version is showing the same content as the other site. (although due to the responsiveness of the page, bloggers are not using the re=” alternate” tag. The site is responsive which means one can use the same themes on the website on the desktop and mobile devices as well). But if you are still willing to apply this tag then here is the perfect tag for it. <link rel=”alternate” href=”your link (URL of your blog)” media=” only screen and (max-width :640px)”>
  5. As I mentioned earlier also that it will be a waste of time to place the canonical tag outside the header tag. So, if you are not using the tag in the section (<head> header section</header>) then Google bots will not be able to grab that tag, and your site will end up in a penalty.
  6. Using multiple canonical tags will also be a waste of time. As search engines are going to ignore those tags and your blog or website will face many errors and many cases Google penalty.
  7. Do to use redirects like 301 and 302. Because this forces search engines to grab one extra URL. In actuality, Google crawls 2 URLs and if this redirection is done permanently instead of temporary redirection, then you can face the Google penalty. And even the 404 code for a long time could make a penalty for your website.

Finally, what I want to Say:

On-page SEO is more important than Off-page SEO because if the On-Page SEO is not done correctly then doing Off-Page SEO is a waste of time. So, canonicalization is an important part of On-page SEO, and this canonical issue must be solved with perfection to get rid of the Google Penalty.

So, if you are still facing any problems with the canonical issue or have any questions, feel free to ask me anything in your comments.

Written by Robin Khokhar
Robin Khokhar is an SEO specialist who mostly writes on SEO. Thus sharing tips and tricks related to SEO, WordPress, blogging, and digital marketing, and related topics.

38 Replies to “Canonicalization: You must solve this canonical issue to avoid Duplicate content”

  1. Hi Robin,

    This is simply amazing:)

    Although it’s old article but helped a lot. Recently have messed url a lot while migrating the site.

  2. Woah,
    Nice peace of well crafted content. The points you covered are really awesome 🙂 everything you wrote was agreeable really cool thanks for writing such a cool post.

  3. Hi Robin,
    This was a very interesting read and has me thinking about my site. I do have Yoast SEO so I’ll have to double check it. Thanks!

    Take care,

  4. Phew! Thank you Robin. Canonicalization is a new word for me. I wonder if a lot of know about it? Very informative a little technical for me lol but worth it, to know about it and how to manage the issue. I will revisit your site

  5. Hi Robin ,
    what a word ,this alone makes me feel curious.
    Have to read this post again to make sure I understand it .
    Good to know about ,Thank you for explaining.

  6. Hi Robin,

    Well, I knew about canonicalization, but wasn’t aware of the possible duplicate content issue with allowing multiple url addresses to load your site. That, I’m leaving to check out now. Thanks for the heads up.

  7. Hey Robin,
    Great post!
    Canonical issues are really important, no one want to afford getting quality and unique content on his/her homepage and get such an issue. For the inner pages, I think Yoast plugin provides you with the ability to set the canonical URL for the post or the page.

    Thanks for sharing.


  8. Hi Robin,
    Its indeed a great joy to read about this post, in fact, i was waiting for such a post, since after our discussion of posting our original post on the pages of HuffPost and the implications we the original publishers faces from Google etc. Nice that you brought out some more lights into this confusion. As I mentioned in one of my comments, the reply to you and David Merril regarding this, I feel that it will not get affected the original publisher. Many people are following these tactics, first posting on their page and then pitch on Huffpost. let us wait and watch. Thanks for sharing this informative piece.
    I am sure many of the people got confused on this subject will clear the doubt by this post.
    Keep writing
    Wish you all the best
    Have a blessed weekend

  9. Hi Robin,

    Thanks for making me aware of Canonicalization. Quite a technical article for me 🙂
    To be honest I have no idea how my blog was installed – whether with or without www.
    Would it be a good idea to redirect at the domain servers, and which would I redirect to which? I normally just refer to my blog without the www when typing the name myself.

    Joy – Blogging After Dark

    1. Hi Joy,
      Yes, Your blog opens up without www but it doesn’t matter that we go with www or non-www but the redirected link must be used with rel. I have explained all in the above post.

  10. Hey Robin,

    There are many phases of understanding the concept of a duplicate content which can tend to Google penalty. Bloggers need to concentrate on their URL so that they can solve such problems.

    It’s good to see the way you have explained about the canonical link. Redirection is always needed of you are using the URL without www.

    Great post.;)
    Enjoy the day.

  11. Hi Robin,
    This is another great and useful article from you in seo.At my early stage of blogging I didn’t know about this canonical issue but later since when I got it I just started taking it seriously and implemented it all of my websites so that it won’t harm my site seo in google’s eye as duplicate content.Thank you very much for this wonderful share,keep up the good work bro.

  12. I always love reading posts on technical seo. You have beautifully described the whole concept of canonicalization. I have also read the same kind of article on shoutmeloud. I recalled it today..


  13. Great info! Thanks so much for putting this together AND making it easy to understand. 🙂
    I think it really help clarify some of our worries 🙂
    Thank you so much Robin for sharing this informative article.

  14. Hi Robin,
    It was really a good post, many of us do not actually know it and we face with this canonical issue, thanks for explaining it keenly, it will help many of them like me, thank you for sharing.

  15. Hi Robin,

    That’s a very handy article on Canonicalization. I came to know about this term later. You have shared a detailed article that will help many to rectify the issue. Thanks for sharing. Take care and have a great week ahead 🙂

  16. Hi Robin

    Thanks for making me know more about canonicalization. It is an interesting concept and one that will benefit content creators. Thanks for sharing. Take Care

  17. Hello Robin, This is the first time I have heard this word canonicalization and you have one an amazing job explaining it and how we can use this Canonicalization tag.

    Great share my friend.
    Chery :))

  18. I have already Used these methods Robin to Install WordPress but I don’t know about manual sites, canonicalization. You have shared and I have learned this method as well. Thanks for shared.

  19. Hi Robin,
    Once again, a very nice and useful article.
    This is very true that Google only rank the website which has quality but Unique content.
    there is no doubt that canonical Issue is one of the biggest issue which should be taken care immediately in order to save your website from any kind of penalty from Google.
    Thank you for sharing such in-depth article with screenshots.
    Vikash Sharma

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