Canonical tags are a key part of SEO. They allow us to handle duplicate content and tell Google what we consider to be the main page. Unfortunately, you’ve probably experienced the case where Google does not honor your canonical tag and instead chooses its own canonical. This is especially an annoyance when dealing with syndicated content. In this article, we’ll explain some of the contributing factors to that issue, which can potentially allow you to convince Google to honor your canonical by taking the proper steps to remedy the issue.
What is a canonical tag?
While you may already know what a canonical tag is, it’s good to have a refresher. A canonical tag is a directive that tells search engines which URL should be considered the primary (or canonical) URL. It’s typically placed via HTML code, but it can also take the form of an HTTP Header tag. You can read all about it on Google’s page about canonical tags.
You’re most likely using a canonical tag to tell Google that a page with parameter tags is not the main page, and to consolidate it into the primary page. It’s the primary method by which we make sure that duplicate pages due to tags etc. are properly associated with the main page. This is the best way we can explicitly tell Google which page we want showing up in the search results.
Google chose a canonical other than the user-declared canonical URL.
On occasion, you’ll be greeted with this lovely message in your coverage report or when you use the URL inspection tool within Google Search Console. It means that Google has decided to ignore your canonical tag and is selecting what it thinks is the better page. You probably won’t like this. We’ll walk through some of the factors that can contribute to canonical tags not being respected.
Note: Keep in mind that Google sometimes does what it wants and it doesn’t matter if everything seems perfect, it won’t change it until it wants to.
Canonical Tag Factor: Internal Linking
Internal links are an important part of effectively ranking your pages, because they carry link equity. When you place a link to the non-canonical version of a URL, you’re pushing that equity to the non-canonical URL. This is fairly common, especially when it comes to certain CMS (Salesforce Commerce Cloud) which link out to a parameterized version of a product URL. If you’re always linking to a non-canonical version of the URL, you’re giving Google a signal that this could be the main version. A few links to non-canonicals is fine, but don’t overdo it.
Canonical Tag Factor: Backlinks
Like internal links, backlinks are also an important part of ranking (I’d say the most important). You really don’t have much control over where someone links, so there’s always the chance someone purposefully links to a non-canonical version of a URL. This would primarily happen if your internal links pointed towards the non-canonical version and they just copy/pasted the link into their article etc. Your best option is to just make sure the default internal link is the canonical version. If Google sees a ton of backlinks pointed towards the non-canonical URL, it’s another signal that maybe it’s the main URL and a better fit.
Note: Old sites often have lots of backlinks pointed to long-dead URLs, so why don’t those rank? On weird occasions they do, but these are almost always redirected towards the new or main URL, which is a stronger signal than the canonical, which is just a hint.
Canonical Tag Factor: Sitemaps
Sitemaps are a list of all of your URLs in an easily accessible format that you can give to Google (and other search engines). They contain what you think are your main URLs and in general are supposed to be clear of 4XX, 3XX and non-canonical URLs. Now if you place the non-canonical URLs in this sitemap, you’re telling Google that this URL is important enough that it needs to be found. Again, this is another signal that’s factored into understanding the main URL.
Let me preface this by pointing out that there is no guarantee this can be solved because Google sometimes does what it wants and ranks the version you don’t want to rank. I’ve had a case where all internal links and sitemaps correctly pointed towards the right URL, but an HTTP version that was over a year old took over the main keyword. The URL redirected and wasn’t found on the site or sitemap, but it still ranked. Eventually Google swapped in the right URL, but there was nothing that could be done to force Google’s hand.
Each of these factors by themselves isn’t a huge signal and Google is smart enough to take everything into consideration. Now imagine that all of the above factors are in play and you’re linking to the non-canonical version of the page both on your site with internal links and inside your sitemap. Additionally you find that most of your backlinks are pointed towards the non-canonical version. With all these factors active, it’s no surprise that Google would consider this to be the main URL.
Note: On occasion you’ll run into the scenario where someone wants to noindex the non-canonical URL. DO NOT DO THIS. Not only does Google tell you that noindex tags and canonical tags should be mutually exclusive, you also lose out on any of the potential traffic you’d have gained. A non-canonical ranking URL is better than no ranking URL.
The easiest way to solve this is to review and fix up your internal linking and sitemaps. The non-canonical version should not be present in the sitemap and if possible, you should not be linking to the non-canonical version (within reason). There are times where it makes sense to link to a non-canonical URL, but you shouldn’t overdo it. Linking to a product that has a parameter that dictates the color makes sense if you’re talking about that color of product. Always linking to that color product in every internal link doesn’t make sense and should be avoided.
On the backlink front, there’s not much you can do. You could reach out to the webmaster of the site and ask them to update it, but there’s no incentive for them to do so. They also might just remove the link entirely, which means you lost that value. I’d avoid this option.
Special Mention: Syndication
When articles are syndicated, sometimes the syndication partner gets full credit for their page, even when they have pointed a canonical towards you. This is an ongoing issue, especially when the site that the syndicated article appears on is much stronger than the original authors site. Most of the time you’re out of luck. In general I’d recommend paying special attention to the fact that you may not rank for the original article you put out. If you’re fine with this, that’s ok, but if you want to guarantee that your article ranks, consider not placing it on other sites.
While there is no guarantee that Google will honour your canonical tag even when you take action, it’s always best to do what you can. Eventually, Google should honour the tag, even if it takes some time. Additionally, it’s a best practice to follow the above steps in general.