Google has provided the things in a better way and provided the accurate results thus fulfilling the requirements of the users. Google has expanded its name to all the organizations whether it is of profitable or non-profitable.
 SEO is applied on all the search engines that are in existence today. Google holds the more traffic on the internet.

What is the Canonical Tag?

This tag is all about duplicate content and preferred content. It is the derivation from canon, which means biblical or secular rules and laws, a standard for judgment. The Canonical Tag helps search engine to make the difference between original pages in relation to duplicate content.
 There are many reasons for duplicate content when it comes to system generated URLs and they are as follows-

Multiple URLs-
 This URL is particularly found on eCommerce a site which helps in creating options for price, color, ratings etc.

Session ID URLs-
 This URL is automatically created on the system. It is applied to track URLs, breadcrumb links, printer friendly versions, and permalinks in certain CMS.

HTTP, HTTPS &WWW-
 Search engines see http://www.example.com, http://example.com, and https://www.example.com as different pages and will definitely crawl on them.

Case-
 Most of the browsers treat upper and lower case same, but the same is not true for search engines and so if the website mixes up then the user needs a canonical tag.

Mobile URL-
 It is used when the user is using a special URL m.example.com for a mobile version of the website.

Country URL-
 When multiple countries use specific URLs, and the content remains the same with only minor differences. In this case, this Country URL is used so as to make separation of the content.

What is URL Canonicalization?

URL Canonicalization is a way of picking one of the preferred destination or URL and makes use of 301 redirects for diverting traffic from the other URLs to preferred URL.

Canonicalization issues

There are two URLs of a website:

http://example.com
http://www.example.com

These both pages (www and a non-www version) show same content which marks in duplicate content issue on Google and it results in penalties. you can fix this issue through canonicalization.

also read:-

How to Correctly Use URL Canonicalization?

Let’s check how to apply URL Canonicalization correctly. For this, a simple rel=”canonical” tag is enough to apply Canonicalization.

For Example:

http://example.com
http://example.com/index.php

There are two URLs on website which results in the same content so you can apply the rel=”canonical” tag, to let search engine know that which is the original and which one is a copy of it. This can save you from duplicate content penalties.

<link rel="canonical" href="http://example.com/" />

in this case, http://example.com is the original url.

Canonical tag should be placed inside the <head> canonical tag </head> as shown below:

<html>
<head>
<link rel="canonical" href="http://example.com/" />
</head>
<body> </body>

</html>
canonicalization tag

When should the user use URL Canonicalization?

Let’s have a look at the few conditions which can be prevented with the help URL Canonicalization and they are-
 • Different URL for one same content
 • Different categories and tags which result in same content
 • Mobile websites display the same content on different URLs.
 • Various available ports
 • When the website has a www and a non-www version
 • In case of sharing syndicated content

Things not to do:-

  • Don’t use a Canonical tag outside of <head>
  • Don’t use multiple Canonical tags on a website
  • Don’t point a Canonical URL to a website with a non-200 status code
  • Don’t use Canonicalization for PageRank Sculpting

Conclusion

Canonical tags help to improve SEO and it increases the ranking of the website, but it needs to be implemented carefully.

Did you check your site for canonicalization issues? If present, what methods are you going to use to sort them?