In the world of search engine optimization (SEO), duplicate content can pose a significant challenge. Websites often generate similar or identical content on multiple pages, which can confuse search engines and harm a website’s ranking. One of the most effective solutions to this problem is the use of canonical tags. In this article, we’ll explore what a canonical tag is, its importance for SEO, and how you can use it to avoid duplicate content issues.
A canonical tag is an HTML element inserted within the
section of a page to indicate to search engines which particular page should be preferred, or canonical, version of a page whenever other pages present duplicate or nearly similar content. This tag instructs search engines which version of a page should actually be indexed and ranked, thus accruing link value to it while saving from the penalties of duplicate content.
The canonical tag points at the canonical URL, which is the preferred page that the owner of the site wishes to be prioritized by search engines.
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Duplicate content issues can arise when similar content is presented on different URLs for different reasons like:
Search engines tend to get confused about which one to rank in their search results when they confront duplicate content. This usually leads to a possibility that both pages lower their ranking because the search engines are likely to distribute the link equity (ranking power), if you like, among them. In the worst-case scenario, Google will go ahead and punish a site for having too much duplicate content.
The canonical tag SEO solution, has rendered concerns of this nature solvable with relative ease by delineating the version of a page that is to be deemed the master page. Thus, search engines assign all the link equity and rankings to the canonical URL, so diluting across duplicate content is avoided.
Canonical tags process works in themselves, but requires precise care. Here are a few steps on how it fits into one's effective use:
The first and most important step of using canonical tags is ascertaining duplicate content on your site. This may include:
Once duplicate content is confirmed, it's time to move on to deciding which page is to be the canonical page. This is usually the page with the highest authority (i.e. has been linked to and has received traffic). If it's a product page that has multiples (i.e. color or size), then in most cases, this would be the main product page to be set as the canonical URL.
After selecting the canonical URL, implement the canonical tag in the
section of the HTML of the duplicate pages. The tag should reference the URL of the canonical version of the page.
Make sure the tag is applied over all versions as stated above and pointed to the canonical URL chosen.
Regularly check these issues since a website changes from time to time in terms of contents and URLs, and therefore the creation of new incidents of duplicate content can occur. Open the tags and update them so that they properly direct to the appropriate pages.
Let's take a concrete example so we can know how to apply canonical tags in a real-life situation. Consider a website selling shoes, where one of its product pages has many color choices. Each of these colors has its separate URL, like this:
Of course, all these pages display the same product, so the content is virtually identical. To avoid duplicate content issues, a canonical tag would have to be added to all three of those pages pointing to the main product page (e.g., https://www.example.com/shoes).
That should be a blue shoe page canonical tag, which will point to the main product page such that search engines will identify the blue shoe page as duplicate and the main page as preferred.
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To enhance the efficacy of canonical tags and reduce potential hurdles, follow the best practices concerning canonical tags:
Always use absolute URLs to set the canonical tags and not relative URLs. An absolute URL means writing out a full URL with the domain name so that a search engine has no doubt in identifying which version of the page is to be taken as canonical, irrespective of its relative position in the website.
On all pages that have some identical content, add canonical tags-not just the original page. Doing so will tell search engines that all versions of the content are duplicates of the canonical page.
Considering pages with unique content (that is, pages that are not duplicates), there is no need for a canonical tag referencing that page. While adding a self-referencing canonical tag (a tag that points to the same URL) has no negative effects on the page's SEO, it is redundant and may lead to some inefficiency.
If there are different versions of the same page (like HTTP and HTTPS versions), the canonical tag should always point to the preferred version to avoid search engines wondering if they are two separate pages.
For e-commerce sites and large sites with complex navigation, duplicate content usually occurs due to the URL parameters or faceted navigation. Incorporating canonical tags on the filtered or faceted versions of pages will help ensure that only the main version of the page gets indexed and not every possible filtered version.
Canonicalising requires some technical steps to do it. To learn how to implement canonical tags, here’s a simple guide:
If you are managing an HTML page website, you can manually add canonical tags by editing the html code of the pages which have duplicate contents, referring to the canonical URL. Add the tag to the
section.
Due to evolution of technologies, most of the modern CMS such as WordPress, Shopify, and Magento have built-in functionality for canonical tags. Configure them either through the SEO plugin or in settings for each page directly. Example: If you are using WordPress, with the Yoast SEO plugin, then the plugin will directly add canonical tags in the pages as you prefer.
Google Search Console cannot directly help with implementing canonicals, but it would alert with duplicate content issues. You put in your canonical tags, then report on the Coverage section to see that Google is recognising your canonicals as you intend.
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Canonical tags are a powerful tool for avoiding duplicate content issues and improving SEO performance. By indicating the preferred version of a page, canonical tags help search engines prioritize the correct content and consolidate link equity. To use them effectively, make sure to:
By doing so, you’ll ensure that your website stays free of duplicate content penalties and ranks better in search engine results, ultimately driving more organic traffic to your site.
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