Missing Canonical Tag

This error appears when a page has no canonical URL defined. Here's what it means and how to fix it.

What this error means

The canonical tag is a line of HTML code that tells Google which is the main version of a page. Without it, search engines have to guess on their own which version to consider — and they don't always get it right. When multiple URLs show the same or very similar content, Google needs to know which one to prioritize. Without a canonical, it may index duplicate versions, split authority across multiple URLs, or simply choose the wrong one. This error is especially common in online stores, blogs with pagination, or sites that generate dynamic URLs with parameters. In these cases, a page can be accessible from multiple addresses without anyone having decided that. Adding the correct canonical is one of those quick actions that helps Google better understand your site and properly distribute authority across your pages.

Why it matters to fix it

Not having a canonical doesn't mean your page will disappear from Google, but it does give Google more room to make decisions that may not work in your favor. And when Google decides on its own, it doesn't always choose what you would. Adding it is quick and the impact can be noticeable in how your content is indexed and ranked.

Impact on SEO rankings

Without a canonical, Google may split a page's authority across multiple URLs showing the same content. That weakens the rankings of all of them instead of concentrating the strength in a single one.

Impact on user experience

Users won't notice this error directly, but they may come across duplicate versions of the same page in search results. That creates confusion and undermines your site's credibility.

Crawling and indexing obstacles

Without a clear signal, Google may index versions of the page that aren't the ones you want to show. Basically, you lose control over what appears in search results.

How to fix it step by step

If this error showed up in your audit, here are the steps to leave it behind.

Step 1

Decide which is the page's primary URL

Before adding anything, you need to be clear about which URL the canonical should point to. It's usually the clean address, without parameters or variations. Review your site's URLs and identify which version you want Google to index.

Step 2

Add the canonical tag in the HTML

Once the primary URL is clear, add the tag inside the page's <head> using the format <link rel="canonical" href="https://yourdomain.com/primary-url/">. You can do this through the SEO plugin you use (Yoast, Rank Math, etc.) or directly in the code.

Step 3

Check that it's been added correctly

Once the change is published, open the page source and look for <link rel="canonical"> inside the <head>. Verify that it appears and that it points to the correct URL.

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