What are you supposed to do to manage duplicate content on your website? Duplicate content with multiple URLs in a site’s content management system can spell possible trouble for that site’s SEO. The solution?
We are going to dive right into what a canonical tag is, how they affect SEO, how to use them for duplicate content purposes, and best practices.
What is a Canonical Tag?
A canonical tag is a piece of HTML that tells search engine crawlers which version of a page or URL you want to appear in search results for a given topic. This is beneficial because it can help you avoid common issues with duplicate content on multiple pages.
A canonical tag is written as rel=“canonical” in the <head></head> section of a page’s HTML source code. The tag specifies your “master” URL or preferred version of the URL for search engine bots to crawl.
A canonical tag and canonical URL are different in form. The tag is the short piece of code and the canonical URL is the full link address of the web page.
Why are Canonical Tags Used for Duplicate Content?
If you have pages on your site with duplicate content, search engine bots and crawlers may either rank both of your pages or only one of your pages. But what if they’re ranking the page you care about less or don’t want as many users to see? With canonical tags, we can guide search engine bots and crawlers to our preferred page to make sure that it is the page we want to rank in search results.
We also use canonical tags to avoid any negative impact from having duplicate content in the first place. Think about it: if you have two pages on your site that are identical or very similar yet serve different purposes and audiences and you want to keep both of the pages, how can you tell Google your intentions so they don’t think you’re just trying to crank out new pages on your site using existing content?
That’s why we use canonical tags: to keep our content and not have to delete it, plus keep it safe, and send search engines in the right direction. By “keep it safe,” we mean outside of a Google penalty.
You see, although it is rare, if you have large-scale duplicate content, you could be issued a manual action if Google perceives it as deceptive. A manual action can be issued by Google if they believe you are acting against their webmaster quality guidelines. The manual actions hold spammers who are rigging the organic search system accountable and punish them for their misactions.
Why Do Duplicate Pages Exist?
After learning about canonical tags, you may be wondering why anyone would have a duplicate content issue on their website. Kind of feels a little odd, right? Why would you have multiple versions of the same page or why would certain pages be pulling in large amounts of content from pages that already exist on your site? Well, to tell you the truth, most of the time duplicate pages are misguided or unintentional due to either content or tech-related reasons.
- The content is about a niche topic so the writing overlaps with something previously written on the site
- The writer may have cloned a blog post and left in a section by accident
- Different writers may have referenced the same sources and research
- Mobile and desktop page versions
- Language-specific page versions
- Comment or page pagination issues
- URL parameters used for attribution purposes
So, if you want the first URL to be the “master” page that Google indexes, you would put a canonical tag on the second URL pointing to the master – this is especially true for the situations above involving technical reasons.
There are different ways to use canonical tags, which we will get to in the next section.
Best Practices for Canonical Tags
Place Canonical Tags in the Right Location
Be sure to place canonical tags in the right location on your site. As mentioned, canonical tags are placed in the HTML header of a webpage. Keep this in mind when you’re thinking about how to manage sending signals to search engines regarding duplicate content.
Make Self-Referential Tags
Canonical tags can be placed on the preferred variation itself and be self-referential. If you want the current URL to be the “master” page, then you can put the tag pointing to this URL on itself. This way, Google will recognize your preferred variation. Self-referencing canonical URLs are definitely an SEO best practice.
Be Wary of Canonicalizing Near-Duplicates
It is possible to canonicalize pages that are not exact duplicates but close in content. However, you want to be careful if you are considering canonicalizing near duplicates. It is debatable whether you should canonicalize pages with very similar but not identical content. The non-canonical versions of the page likely will not be able to rank even though it is not the exact same page.
Don’t Confuse Google
Sending mixed signals to Google is never a good idea. In terms of canonicalization, we mean that you should not canonicalize Page 1 to refer to Page 2 and then do the opposite and have Page 2 canonicalized to refer to Page 1. This is also true for not including non-canonical URLs in your sitemap. It defeats the purpose and only confuses Google.
According to Ahrefs, “Non-canonical pages in sitemaps send a misleading signal to search engines, instructing them to index the URLs that declare a different URL as their canonical version.”
Don’t Internally Link to Non-Canonical Pages
As mentioned, you want to make sure you’re sending the right signals to Google. The best way to do this is to support the canonical version of a page and not support the non-canonical page. What this basically means is don’t internally link to the non-canonical page version. You want to pass link juice to the canonical version, not the non-canonical version.
Hopefully, these best practices help you stay on top of duplicate content and canonicalization. Lastly, we are going to talk about how to audit canonical tags.
Here’s a great video from Google’s very own John Mueller for more information.
How to Audit Canonical Tags
Auditing canonical tags for SEO performance is essential to success. You will want to check if a page has a canonical tag, make sure it points to the correct place, and check that the page is being crawled and indexed.
The most basic way to audit canonical tags is to view your page’s source code. You can right-click and select view-source or on Chrome, go to developer tools on the page. This should open up your source code. Look in the <head></head> section to see if a rel=“canonical” tag is present.
Moz also offers a simple and free SEO toolbar that will show you if there’s a canonical tag on any page.
Another option is to use your SEO software to bulk audit pages. Most software will have this option. It saves you time and energy to do SEO audits this way.
Since you are now familiar with what a canonical tag is, it’s time to implement them and run audits occasionally. Make sure you are utilizing these tags to manage your duplicate content and maximize your chances of ranking on search engine results pages.