If you’ve run a quick check with the SEO Action Plan Chrome extension and saw the message Canonical URL is missing, then this article will help you. This is a missing canonical URL is a common issue and pretty easy to fix once you know what it means.
Let’s go through what a canonical URL is, why it matters for SEO, and how you can add it to your site.
What Is a Canonical URL? #
A canonical URL is a way of telling search engines which version of a page is the original or preferred one.
For example, these two URLs might lead to the same content:
https://example.com/pagehttps://example.com/page?ref=newsletter
Even though they look different, they show the same thing. Without a canonical tag, search engines might treat them as two separate pages. That can cause duplicate content issues and split your SEO efforts. So it’s recommended to have the self-canonical URL being output on the page to make the search engines index the pages correctly.
Why This Matters #
When you don’t define a canonical URL, search engines have to guess which page to index. That guess isn’t always right. Your ranking signals can get scattered across multiple versions of the same page, and that weakens your overall visibility in search results.
It’s a small tag, but it does an important job.
How to Check for a Canonical Tag #
The easiest way is to use the SEO Action Plan extension:
- Open the page you want to check.
- Click the SEO Action Plan icon in your browser.
- Go to the SEO tab.
- Look for “Canonical URL” in the report.
If it says missing, that means the tag isn’t present in the page’s source.
You can also check manually by viewing your page’s source code. Look in the <head> section for something like this:
<link rel="canonical" href="https://example.com/your-page/" />
If you don’t see that, it’s time to add it.
How to Add a Canonical URL to your webpage #
On WordPress #
If you use an SEO plugin, you might already have this handled.
- Yoast SEO: Automatically adds canonicals. You can review or customize it under the “Advanced” tab for any post or page.
- All in One SEO (AIOSEO): This also includes canonical settings within the page or post editor.
- Rank Math: Look for the Canonical URL field when editing a page.
On Shopify #
Shopify usually adds canonical tags for you. But if your store uses apps or custom code that affects URLs, you should check your theme files under theme.liquid to make sure everything is correct.
On Webflow #
You can enable or set canonical tags under each page’s SEO Settings. If you need something custom, Webflow also allows you to add code to the page’s <head> section.
On Wix and Squarespace #
These platforms add canonicals automatically in most cases. However, if you encounter issues, you may need to contact support or check your site’s source code for confirmation.
How to Add It Manually #
If you’re editing raw HTML or working on a custom setup, you can add a canonical tag like this:
<link rel="canonical" href="https://yourdomain.com/preferred-url/" />
Make sure to place it inside the <head> section of your HTML and the URL should be the same page that you prefer to index, and not the one having any parameters on it. Then reload the page and check again with the SEO Action Plan extension to confirm it’s working.
Wrapping Up #
Missing a canonical URL isn’t the end of the world, but fixing it helps your site stay clean and consistent in the eyes of search engines. Whether you’re using WordPress, Shopify, Webflow, or something custom, there’s always a way to add it.
The SEO Action Plan extension makes it simple to spot these issues while browsing your site. Keep it installed to catch issues early on and avoid future SEO headaches.