Canonical Tags: A Simple Guide for Beginners

Hoping to realize what sanctioned labels are, and how to utilize them to keep away from feared copy content issues?

Sanctioned labels are the same old thing. They’ve been around beginning around 2009 — the most amazing aspect of 10 years.

Google, Microsoft and Yippee joined to make them. Their point? To give site proprietors a method for tackling copy content issues rapidly and without any problem.

Do they work? Indeed, impeccably… yet provided that you know how to utilize them!

In this aide, you’ll learn:

  • What a canonical tag is
  • What a canonical tag looks like
  • Why canonical tags are important for SEO
  • Canonicalization best practices
  • How to implement canonical tags
  • How to avoid common canonicalization mistakes
  • How to find and fix canonicalization issues

What is a canonical tag?

A standard tag (rel=”canonical”) is a piece of HTML code that characterizes the principal rendition for copy, close copy and comparable pages. As such, on the off chance that you have something similar or comparative substance accessible under various URLs, you can utilize authoritative labels to indicate which adaptation is the primary one and hence, ought to be recorded.

What does a canonical tag look like?

Standard labels utilize straightforward and steady language structure, and are put inside the <head> part of a website page:

This is the thing each piece of that code implies in plain English:

  1. link rel=“canonical”: The link in this tag is the master (canonical) version of this page.
  2. href=“”: The canonical version can be found at this URL.

Why are canonical tags important for SEO?

Google could do without copy content. It makes it harder for them to pick:

  1. Which version of a page to index (they’ll only index one!)
  2. Which version of a page to rank for relevant queries.
  3. Whether they should consolidate “link equity” on one page, or split it between multiple versions.

Too much duplicate content can also affect your “crawl budget.” That means Google may end up wasting time crawling multiple versions of the same page instead of discovering other important content on your website.


Constraining Google to sit around slithering copy content is, obviously, something that ought to be stayed away from if conceivable. Nonetheless, Google expresses that it’s anything but an issue for most destinations.

 In the event that new pages will more often than not be slithered that very day they’re distributed, creep labels address this multitude of issues. They let you let Google know which variant of a page they ought to file and rank, and where to merge any “interface value.”

Neglect to indicate a sanctioned URL, and Google will assume control over issues.

financial plan isn’t something website admins need to zero in on. In like manner, in the event that a site has less than two or three thousand URLs, more often than not it will be slithered productively.

Authoritative labels address this multitude of issues. They let you let Google know which variant of a page they ought to file and rank, and where to merge any “interface value.”

Neglect to indicate a sanctioned URL, and Google will assume control over issues.

Depending on Google like this is certainly not an extraordinary thought. They might choose a rendition of your page that you would truly prefer not to be standard.


Google expresses that they as a rule regard the standard URL you set, yet not dependably. That is on the grounds that canonicals labels are hints not mandates. However long they are regarded then any signs, for example, connections ought to merge to the sanctioned URL.

Utilizing sanctioned label best practices additionally mitigates the gamble of Google seeing a bothersome rendition of the page as accepted.

But I don’t have duplicate content, do I?

Considering that you presumably haven’t been distributing similar posts and pages on different occasions, it’s not difficult to expect that your site has no copy content.

Yet, web indexes slither URLs, not site pages.

That implies that they see and as novel pages, despite the fact that they’re a similar page with indistinguishable or comparative substance.

These are called defined URLs, and they’re a typical reason for copy content, particularly on internet business locales with faceted/sifted route.

For instance, Earthy colored Sack Dress sells shirts. This is the URL for their fundamental class page:

In the event that you channel for just XL shirts, a boundary is added to the URL:

On the off chance that you, additionally channel for just blue shirts, one more boundary is added:

These are discrete pages in Google’s eyes, despite the fact that the substance is just possibly unique.

However, it’s not simply web based business destinations that succumb to copy content.

Here are a few other normal reasons for copy content that apply to a wide range of sites:

  • Having parameterized URLs for search parameters (e.g.,
  • Having parameterized URLs for session IDs (e.g.,
  • Having separate printable versions of pages (e.g., and
  • Having unique URLs for posts under different categories (e.g., and
  • Having pages for different device types (e.g., and
  • Having AMP and non-AMP versions of a page (e.g., and amp.example/page)
  • Serving the same content at non-www and www variants (e.g., and
  • Serving the same content at non-https and https variants (e.g., and
  • Serving the same content with and without trailing slashes (e.g., and
  • Serving the same content at default versions of the page such as index pages (e.g.,, etc.)
  • Serving the same content with and without capital letters (e.g., and

In these circumstances, the legitimate utilization of standard labels is critical.

Besides, cross-space copy content issues are likewise a thing. On the off chance that you’re partnering content it’s best practice to utilize a self-referential standard label on your article and to have the partnered content determine you as the sanctioned form with a cross-space accepted tag.

This doesn’t necessarily keep the partnered content from appearing in the indexed lists, yet it diminishes its gamble outclassing the first.


A few destinations will won’t add a standard connection. In such cases, it ultimately depends on you whether you need to face the challenge.

The basics of canonical tag implementation

Canonicals are not difficult to carry out. We’ll examine four distinct ways for doing that in a second. In any case, regardless of which technique you settle on, there are five brilliant guidelines that you ought to keep in mind consistently.

Rule #1: Use absolute URLs

Google’s John Mueller states that it’s best practice not to utilize relative ways with the rel=”canonical” interface component.

Rule #2: Use lowercase URLs

Since Google might regard capitalized and lowercase URLs as two unique URLs, you need to initially make a point to compel lowercase URLs on your server and afterward utilize lowercase URLs for your sanctioned labels.

Rule #3: Use the correct domain version (HTTPS vs. HTTP)

Assuming you exchanged over to SSL, ensure that you don’t proclaim any non-SSL (i.e., HTTP) URLs in your sanctioned labels. Doing so can hypothetically prompt disarray and surprising outcomes. In the event that you’re on a safe space, guarantee that you utilize the accompanying form of your URL:


 If you’re not using HTTPS then the opposite is true. 

Rule #4: Use self-referential canonical tags

I suggest [using a] self-referential authoritative in light of the fact that it truly makes it clear to us which page you need to have filed, or what the URL ought to be the point at which it is listed.

Regardless of whether you have one page, once in a while there are various varieties of the URL that can pull that page up. For instance, with boundaries eventually, maybe with upper lower case or www and non-www. These things can be somewhat tidied up with a rel sanctioned tag.

On the off chance that you’re uncertain how a self-referential sanctioned functions, fundamentally a standard label on a page focuses to itself. For instance, in the event that the URL were page, a self-referring to standard on that page would be:

<interface rel=”canonical” href=” page”/>

Most present day famous CMS’ add self-referring to URLs consequently, yet you’ll have to have your designer hardcode this if utilizing a custom CMS.

Rule #5: Use one canonical tag per page

On the off chance that the page has different authoritative labels, Google will overlook both.

In instances of numerous announcements of rel=canonical, Google will probably overlook all the rel=canonical hints.

How to implement canonicals

There are five known ways of indicating accepted URLs. These are known as canonicalization signals:

  1. HTML tag (rel=canonical)
  2. HTTP header
  3. Sitemap
  4. 301 redirect*
  5. Internal links

For pros and cons of each method, see Google’s official documentation.

1. Setting canonicals using rel=“canonical” HTML tags

Utilizing a rel=canonical tag is the least difficult and most clear method for indicating a sanctioned URL.

Essentially add the accompanying code to the <head> part of any copy page:

<connect rel=”canonical” href=” page/”/>


Suppose that you have an internet business site selling shirts. You need shirts/to be the sanctioned URL, despite the fact that that page’s substance is available through different URLs (e.g., shirts/)

Just add the accompanying standard tag to any copy pages:

<interface rel=”canonical” href=” shirts/”/>

Note that in the event that you’re utilizing a CMS, you don’t have to play with the code of your page. There’s a simpler way.

Setting canonical tags in WordPress:

Introduce Yoast Web optimization and self-referring to standard labels will be added consequently. To set custom canonicals, utilize the “High level” segment on each post or page.

Setting canonical tags in Shopify:

Shopify adds self-referring to sanctioned URLs for items and blog entries naturally. To set custom sanctioned URLs, you’ll have to alter the layout (.fluid) documents straightforwardly.

This string has some data on the best way to do that.

Setting canonical tags in Squarespace:

Squarespace adds self-referring to URLs as a matter of course as well. Be that as it may, just like with Shopify, you really want to alter the code straightforwardly to add a custom standard URL.

Setting canonicals in HTTP headers

For reports like PDFs, it’s basically impossible to put authoritative labels in the page header since there is no page <head> segment. In such cases, you’ll have to utilize HTTP headers to set canonicals. You can likewise utilize a sanctioned in HTTP headers on standard site pages.


Envision that we make a PDF form of this blog entry and host it in our blog subfolder (*).

This is what our HTTP header could resemble for that document:

HTTP/1.1 200 alright

Content-Type: application/pdf

Interface: < labels/>; rel=”canonical”

Setting canonicals in sitemaps

Google expresses that non-sanctioned pages ought not be remembered for sitemaps. Just sanctioned URLs ought to be recorded. That is on the grounds that Google sees the pages recorded in a sitemap as recommended canonicals.

Nonetheless, they won’t generally choose URLs in sitemaps as canonicals.

We don’t ensure that we’ll consider the sitemap URLs to be sanctioned, however it is a straightforward approach to characterizing canonicals for an enormous site, and sitemaps are a helpful method for let Google know which pages you think about most significant on your site.

Setting canonicals with 301 redirects

Utilize 301 sidetracks when you need to redirect traffic from a copy URL and to the standard variant.


Suppose your page is reachable at these URLs:


Choose one URL as the canonical and redirect the other URLs there.

You ought to do likewise for secure HTTPS/HTTP and www/non-www variants of your site. Pick one sanctioned form and divert the others to that adaptation.

For instance, the standard variant of is the HTTPS non-www URL ( Each of the accompanying URLs divert there:


Read our full guide to implementing 301 redirects.

Internal Links

How you interface starting with one page then onto the next all through your site is a canonicalization signal.

Google Website admin Patterns Examiner John Mueller covers the signs used to decide accepted URLs in this #AskGoogleWebmasters video:

The more steady you are with these signs, the simpler it will be for web search tools to decide your favored accepted URL. As referenced by John in the video, Google likewise has an inclination for HTTPS over HTTP URLs, and for prettier URLs.

Common canonicalization mistakes to avoid

Canonicalization is a to some degree complex subject. In that capacity, there are a great deal of errors and confusions about how to canonicalize appropriately.

Here are a few normal errors individuals while attempting to canonicalize:

Mistake #1: Blocking the canonicalized URL via robots.txt

Impeding a URL in robots.txt keeps Google from slithering it, implying that they’re not able to see any sanctioned labels on that page. That, thus, keeps them from moving any “interface value” from the non-accepted to the sanctioned.

Mistake #2: Setting the canonicalized URL to ‘noindex’

Never blend noindex and rel=canonical. They’re disconnected directions.

Google will as a rule focus on the standard tag over the ‘noindex’ tag, as John Mueller states here. In any case, it’s still awful practice. On the off chance that you need to noindex and canonicalize a URL, utilize a 301 divert. In any case, use rel=canonical.

Mistake #3: Setting a 4XX HTTP status code for the canonicalized URL

Setting a 4XX HTTP status code for a canonicalized URL has a similar impact as utilizing the ‘noindex’ tag: Google will not be able to see the standard tag and move “interface value” to the sanctioned variant.

Mistake #4: Canonicalizing all paginated pages to the root page

Paginated pages ought not be canonicalized to the primary paginated page in the series. All things considered, self-referring to canonicals ought to be utilized on undeniably paginated pages.

Why? As Google’s John Mueller expressed on Reddit, this is ill-advised utilize the rel=canonical.

The primary thing to keep away from, since this post is about canonicalization, is to utilize the rel=canonical on page 2 highlighting page 1. Page 2 isn’t comparable to page 1, so the rel=canonical like that sounds mistaken, truly.

Mistake #5: Not using canonical tags with hreflang

Hreflang labels are utilized to determine the language and geological focusing of a site page.

Google expresses that while utilizing hreflang, you ought to “determine a standard page in a similar language, or the most ideal substitute language if a sanctioned doesn’t exist for a similar language.”

Mistake #6: Having multiple rel=canonical tags

Having different rel=canonical labels will make them probably be overlooked by Google. Generally speaking this happens in light of the fact that labels are embedded into a framework at various focuses like by the CMS, the topic, and plugin(s). To this end numerous modules have an overwrite choice intended to ensure that they are the main hotspot for authoritative labels.

Another region where this may be an issue is with canonicals added with JavaScript. On the off chance that you have no sanctioned URL determined in the HTML reaction and, add a rel=canonical tag with JavaScript then it ought to be regarded when Google delivers the page. Nonetheless, in the event that you have a standard determined in HTML and trade the favored form with JavaScript, you are conveying conflicting messages to research.

Mistake #7: Rel=canonical in the <body>

Rel=canonical ought to just show up in the <head> of a record. A sanctioned tag in the <body> segment of a page will be overlooked.

Where this can turn into an issue is with the parsing of a record. While the source code of a page might have the rel=canonical label in the right area, when the page is really developed in a program or delivered by a web search tool, a wide range of things, for example, unclosed labels, JavaScript infused, or <iframes> in the <head> segment can cause the <head> to end rashly while delivering. In these cases a standard tag might be unintentionally tossed into the <body> of a delivered page where it won’t be regarded.

How to find and fix canonicalization issues on your site

It’s not difficult to commit errors with canonicalization, so it pays to consistently review your site for issues connected with authoritative labels and fix them quickly.

For this, you can utilize Ahrefs’ Site Review apparatus.

Webpage Review creeps your site for more than 100 Website optimization issues, including those connected with authoritative labels.

Here are the twelve standard tag-related issues Site Review might find, and how to fix them:

Canonical points to 4XX

This cautioning triggers when at least one pages are canonicalized to a 4XX URL.

Why it’s an issue

Web crawlers don’t record 4XX pages since they don’t work. Thus, they’ll disregard any standard labels highlighting such pages and frequently wind up ordering some unacceptable (non-accepted) adaptation of the page.

Instructions to fix

Survey the impacted pages and supplant the dead (4XX) authoritative connections with connections to working (200) pages that you need filed.

Canonical points to 5XX

This cautioning triggers when at least one pages is canonicalized to a 5XX URL.

Why it’s an issue

5XX HTTP status codes demonstrate server issues, which bring about a difficult to reach authoritative page. Google is probably not going to list out of reach pages, so may overlook the standard.

Instructions to fix

Supplant any incorrect authoritative URLs with substantial URLs. Check for server misconfigurations if the predetermined standard appears to be right. Note that this might be a brief issue if the slither occured when your site was down for support or your site’s server over-burden.

Canonical points to redirect

This cautioning triggers when at least one pages is canonicalized to a diverted URL.

Why it’s an issue

Canonicals ought to constantly highlight the most legitimate form of a page. This isn’t true with diverting URLs. Subsequently, web indexes might misjudge or overlook the accepted.

The most effective method to fix

Supplant the standard connections with direct connections to the most definitive rendition of the page (i.e., one that profits a 200 HTTP status code and doesn’t divert).

Duplicate pages without canonical

This cautioning triggers when at least one copy or fundamentally the same as pages exist that don’t indicate a sanctioned rendition.

Why it’s an issue

Since no authoritative is determined, Google will endeavor to distinguish the most suitable rendition to show in list items themselves. This may not be the adaptation you need filed.

Step by step instructions to fix

Audit the gatherings of copies. Pick one authoritative rendition that ought to be filed in the list items. Indicate this as the standard variant across all copies (and add a self-referring to sanctioned tag to the authoritative form).

Hreflang to non-canonical

This cautioning triggers when at least one pages determine a non-sanctioned URL in their hreflang explanations.

Why it’s an issue

Joins in hreflang labels ought to constantly highlight the authoritative pages. Connecting to a non-standard variant of a page from hreflang explanations can befuddle and deceive web crawlers.

The most effective method to fix

Supplant joins in the hreflang comments of impacted pages with their sanctioned.

Canonical URL has no incoming internal links

This cautioning triggers when at least one determined accepted URLs have no inward approaching connections.

Why it’s an issue

Standard URLs without interior connections are difficult to reach to site guests. Some place on the site, they’re being coordinated to a non-standard variant of the page all things being equal.

Step by step instructions to fix

Supplant any inward connections to canonicalized pages with direct connections to the standard.

Non-canonical page in sitemap

This cautioning triggers when at least one non-accepted pages are recorded in the sitemap.

Why it’s an issue

Google expresses that you should exclude non-accepted URLs in your sitemap. Reason being, they see pages in sitemaps as recommended canonicals. You ought to just rundown pages that you need filed in sitemaps.

Instructions to fix

Eliminate non-accepted URLs from your sitemap.

Non-canonical page specified as canonical one

This cautioning triggers when at least one pages determine a sanctioned URL which is likewise canonicalized to an alternate page. This makes a “sanctioned chain” where page An is canonicalized to page B, which is then canonicalized to page C.

Why it’s an issue

Authoritative chains might befuddle and deceive web crawlers. Subsequently, they might confuse or overlook the predefined sanctioned.

The most effective method to fix

Supplant non-standard connections in the sanctioned labels of impacted pages with direct connections to the authoritative. For instance, in the event that page An is canonicalized to page B, which is canonicalized to page C, supplant then standard connection on page A with a connection to page C.

9. Open Graph URL n ot matching canonical

This cautioning triggers when there’s a bungle between the predetermined standard and the Open Chart URL on at least one pages.

Why it’s an issue

In the event that the Open Chart URL doesn’t match the sanctioned, then a non-standard variant of a page will be shared on informal organizations.

Step by step instructions to fix

Supplant the Open Diagram URL on impacted pages with the accepted URL. Ensure the two URLs are something similar.


 URLs inside Open Graph tags must be absolute and utilize the http:// or https:// protocols, as is the case with canonicals. 

Canonical from HTTPS to HTTP

This cautioning triggers when one or safer (HTTPS) pages determine a non-secure (HTTP) variant as the sanctioned.

Why it’s an issue

HTTPS is a positioning variable, so it’s a good idea to indicate secure variants of pages as standard where conceivable.

The most effective method to fix

Divert the HTTP page to the HTTPS same. In the event that that is unrealistic, add a rel=”canonical” connect from the HTTP variant of the page to the HTTPS one.


 Google also lists implementing HSTS as a potential solution.

11. Canonical from HTTP to HTTPS

This cautioning triggers when at least one non-secure (HTTP) pages indicate a solid (HTTPS) form as the sanctioned.

Why it’s an issue

HTTPS is liked over HTTP. Having a HTTP variant of a page then determining the HTTPS rendition as sanctioned is irrational.


 This probably won’t cause an immense issue, however it’s as yet worth fixing if conceivable.

Step by step instructions to fix

Execute a 301 divert from HTTP to HTTPS. You ought to likewise supplant any inner connections to the HTTP form of the page with joins straightforwardly to the HTTPS adaptation.

12. Non-canonical page receives organic traffic

This cautioning triggers when at least one non-authoritative pages appear in query items and get natural pursuit traffic (which shouldn’t occur).

Why it’s an issue

Either your authoritative labels are set up mistakenly or Google has decided to overlook the predefined accepted.

Step by step instructions to fix

Check that the rel=canonical labels are set up accurately on undeniably detailed pages. In the event that that is not the issue, utilize the URL Review apparatus in Google Search Control center to see whether they consider the predefined authoritative URL as standard. In the event that there’s a bungle, explore why this might be the situation.

Final thoughts

  • Alternate page with proper canonical tag. This shows pages where you have specified an alternate page with a canonical tag and it was respected. Basically, it’s working as intended to consolidate to a page you chose.
  • Duplicate without user-selected canonical. There are duplicate pages and none of them have a chosen canonical. In this case Google has chosen one for you, so if it’s not the one you prefer then you should add a rel=canonical tag.
  • Duplicate, Google chose a different canonical than user. This shows cases where Google chose to ignore your suggested canonical but still chose a different version to show in the index.
  • Duplicate, submitted URL not selected as canonical. This is also a case of a canonicalization signal (being submitted in a sitemap) being ignored. There is no explicitly marked canonical URL in this set of duplicate pages and in this case Google believes that another URL besides the one you submitted should be shown in the index.
Total Views: 53 ,

Leave a Reply

Your email address will not be published. Required fields are marked *