A canonical URL is the most authoritative URL when several URLs contain similar content or there is duplication of content through several URLs. It is one of the most important SEO factors that helps search engines set a page version located at the URL as the primary or canonical one. This is done through a rel=“canonical” link element within the head part of the HTML tags.

The canonical tag avoids problems such as duplicate content or content duplication. Without it, it may take a search engine a long time, probably even to identify the page that has to be ranked for specific keywords, since there will be a general dilution of search engine rankings.

Why is a canonical URL valuable for SEO?

Google, for example, will tend to rank the most authoritative and relevant version of that page in the search results. When multiple URLs have identical or nearly identical content, it can lead to the following issues:

Duplicate Content: Some search engines place duplicate content into spam, or they do not rank such sites high.

Rank Dilution: In contrast with one page only being able to gain the high rankings, it can be divided out among several pages.

Crawl Budget Wastage: Googlebot may spend a lot of time indexing multiple variants of similar or related pages while there are many more relevant and unique ones out there.

By having a canonical URL, you tell the search engines where the proper page is and prevent issues described above. This is helpful in getting the link equity together and making the rankings better.

To learn more about SEO optimization, continue with the SEO Best Practices guide outlined for your use here.

How to Fix Canonical Issues?

Solving canonical issues includes proper setup of canonical web addresses regarding your own website. Misconceived or improperly employed, canonical tags can cause botched traffic redirects, rank diversions, or search engine indexing of the wrong page. Here is a guide on how to deal with most of the times encountered canonical problems as listed below.

1. Identify Duplicate Content

It is, however, important first to distinguish between canonical problems and duplicate content. Most SEO crawl tools, like Google Search Console, Screaming Frog SEO Spider tool, or Sitebulb, among others, can be used to determine pages with similar content.

Steps to identify duplicate content:

When you want to verify whether two or more pages have the same meta description or title, you should employ the Google Search Console.

The use of SEO crawlers to recognize duplicated URLs should also be employed.

Always use an automatic plagiarism checker, but in case it fails to do its job properly or rarely, then it is recommended to check for duplicate content manually.

In either of the cases mentioned above, try to figure out which page is the most authoritative or should be ranked the higher. This one is the canonical URL you’re going to use.

2. Place a canonical tag within the HTML header.

If you are set on the preferred version of the page, the next step is to put a canonical tag in the HTML of the non-preferred or ‘copycat’ page.

Example of a canonical tag in HTML:

The output is: head>

⁣link rel="canonical" href="https://www.example.com/your-preferred-page" />

The output is:

This informs the search engines that the page in the href attribute is the canonical version where all the ranking factors are to be assigned.

Best practice: Be sure that you are making the canonical link to a page that stands and is.Related: If you link to a non-existing page, you could perhaps lose traffic and your rankings as well.

3. Learn how to address pagination problems using canonical tags.

Pagination is also a potential issue in the development of the duplicate content. For instance, a blog or product page that uses pagination has multiple pages containing similar content. In such cases, an opportunity to address this issue can be to provide rel=“canonical” pointing to the page version without paginated subpages.

Example of handling pagination with a canonical tag:

If you have a paginated blog with multiple pages, such as page 1, page 2, and so on, you should then put the canonical to the next pages in the link.

The output is:

link rel="canonical" href="https://www.example.com/blog-post-main-page" />

4. Always avail yourself of the use of canonical tags for content syndication.

Content syndication refers to reposting content from one website to another. If the canonical tag is not set, then both the first content and the content that has been syndicated can be considered duplicates by search engines.

To address this issue, one has to include the canonical tag at the end of the content and make it link to the original articles. This helps to make sure that the search engines will allot the ranking signals to the original work or link.

5. Algorithm to Repair Canonical Errors in URL Parameters

They can cause a problem known as duplicate content from time to time, through URL parameters. For instance, where a number of landing page elements include different tracking parameters, such as ?utm_campaign, ref, or source, to a single product page, then one may end up with many original URLs to the same content.

To instruct the search engine that this parameterized URL is actually one with the original page, use the canonical tag. It is also important in Google Search Console to set up parameters for URLs to prevent problems with the indexation.

6. Combine Large and Small Versions of Your Website

If your website is accessible via both www and non-www versions (e.g., https://www.example.com and https://example.com), you have a choice to make about the so-called canonical address.

It is better to set the preferred version by using a canonical tag or make a 301 redirect from the unwanted version to the preferable one.

7. Canonical tags are instructions that browsers should follow while rendering a page. The most common problems associated with canonical tags are broken or incorrect canonical tags.

Lack of, or mistakes in, tags also mean that the search engines will crawl the wrong web page. This can occur if, by mistake, you point the canonical tag to a page that either does not exist or is rather unrelated.

There are many other ways you can manually, or by using tools such as Google Search Console or Screaming Frog, see if there are any canonical tags on your website that are broken or implemented wrongly.

8. The “Self-Referencing” Canonical Tag for Single Pages

In case you do not have another page that is a copy or branch of the current page, you can set up a self-referring canonical tag. This is reassuring to the search engine that the page is its own preferred version of the page, and all future frustrations are avoided. 

The output is:

link rel="canonical" href="https://www.example.com/your-page" />

9. Canonical tags: Check and Change Them Periodically

In this course, content sometimes undergoes alteration, or new pages are created, or, on the flip side, some pages are deleted. It is very important to regularly audit your site's canonical tags to ensure they are always pointing to the right URLs.

Using automated tools and monitoring through Google Search Console can help you stay updated and make necessary corrections.

For a more in-depth guide on how to audit and update canonical URLs, visit our article on SEO Site Audits.

Conclusion

This would ensure proper canonical URL configuration and be an important aspect of maintaining the health of SEO, ranking pages, and avoiding penalties such as duplicate content issues. With proper canonical tag implementation, you can merge ranking signals, avoid penalties, and give search engines a clear indication of which version is preferable.

Monitoring and fixing canonical issues regularly will keep your website in optimal condition for both users and search engines.