Somewhere deep in the code of pretty much every page on your website, there’s a little tag most business owners have never heard of, silently revealing to Google which version of that page counts. When correctly configured, you won’t even notice it’s there. When it’s not, it can make an entire page disappear from search results, or worse, tell Google to rank the wrong page entirely. That tag is called a canonical tag, and it’s one of those things that you don’t notice until it’s already causing issues.
What Does a Canonical Tag Do?
A canonical tag is an HTML snippet that lives in the code of a page telling search engines, “If you see this page and some other versions of it floating around, this is the one that counts.” In other words, it points search engines toward a single, authoritative URL for a given piece of content.
Canonical tags matter, because the same piece of content can sometimes be accessed through dozens of different URLs without anyone intending it that way: non-www vs. www versions, with or without a trailing slash, with tracking parameters appended to the URL, etc. A canonical tag is how you tell search engines which version should get the credit.
How a Tiny Detail Can Cause a Big Problem
Here’s what makes canonical tags tricky: they’re fairly easy to get right, and just as easy to get wrong without anyone noticing until your rankings start slipping. Here are a few canonical mistakes that we’re all guilty of making:
Pointing to the Wrong Page Entirely
If a canonical tag accidentally points to a different page than the one it’s attached to (say, due to copying a snippet from a website template), it can tell Google to ignore that page in favor of a totally different page. You might have a very good page that’s suddenly not ranking anywhere because Google’s pointed to the wrong canonical URL.
Canonicalizing Everything to the Homepage
This is fairly common, often leftover from installing a website theme or template that didn’t have this set up properly. It canlead to Google believing that all of your content is one big homepage that needs to be the only thing that ranks.
Omitting Canonical Tags Altogether
Without a canonical tag, Google is left to figure out on its own which version of a page to rank, sometimes with good results, sometimes not. That can lead to the wrong URL being treated as the primary version or create unnecessary duplication signals across similar pages.
Inconsistent Signals
If you have a canonical URL set up one way but your sitemap points somewhere else, or you have inconsistent internal linking, Google may get mixed messages about which version of the page you’re actually recommending.
Why Canonical Tag Problems Are Easy to Overlook
The reasons are quite similar to why having duplicate content is a problem: canonical tags tend to be set once (usually during a website migration or redesign), and then not touched again. Usually it’s fine, until one of a handful of canonical configurations change:
- Your website moves to a new platform. You make a few tweaks, but nothing about your website’s structure changes; search engines will still see your original URLs. However, in the case of a canonical tag going awry, there’s now a different URL assigned as the canonical for the whole site.
- Your website is redesigned. While you’re at it, you forget to review your canonical tags. Now, your website’s URLs are all shifted around, and all pages point back to the homepage instead of their actual content, possibly signaling to Google that only the homepage is canonical.
- One of your plugins or modules updates without your noticing. Suddenly, your website’s canonical URL is no longer what you had set up before.
- You have multiple URLs for the same content. As a result, search engines are choosing different ones without any clarification.
All these little things can go wrong and nobody notices until your rankings suddenly take a hit.
How Can I Tell if This is Affecting Me?
You don’t need to become an SEO expert to spot if this is an issue. In fact, it’s wise not to DIY this if you’re not sure what you’re doing. Here are some questions to ask yourself:
- Do you have pages that you know exist that aren’t appearing in search?
- Do you have pages that rank on Google but the URL shown isn’t quite right?
- Did your search traffic suddenly decline?
These can be signs of a canonical tag issue and warrant further investigation, though they are not definitive proof.
Are Canonical Tag Issues Easy to Fix?
Unlike the problem of having duplicate content, fixing a canonical tag issue doesn’t usually mean overhauling your whole site. A fix just involves correcting whatever set of canonical tags are wrongly pointing somewhere they shouldn’t be and ensuring everything else on your site points to the same canonical URL (sometimes that just takes updating a few canonical tags in your website’s code).
It’s one of those small website details that can easily go unnoticed but have a significant impact when something isn’t set up correctly. It’s also surprisingly easy to get wrong without realizing it, since nothing about the website will necessarily look or feel broken.
What We Can Do
Our team at Magna Technology understands the importance of keeping those canonical tags in check. If you’re seeing a decline in traffic, your site is missing pages from Google, or you’d just like to be sure nothing’s amiss, we’re here to help. We build canonization health into our SEO audits for clients to detect if this little bug could be bugging out your site. Give us a call today at (617) 249-0539 or fill out our contact form to start the conversation.