If you're a WordPress user looking to optimize your website for search engines, you may have heard of canonical tags.
These small but powerful HTML elements can help you manage duplicate content, improve your site's SEO, and provide clear signals to search engines about your preferred page versions.
In this article, we'll dive into what canonical tags are, why they matter for WordPress users, and how you can implement them on your website.
Whether you're a beginner or an experienced WordPress user, understanding canonical tags is helpful for maintaining a well-structured and search-engine-friendly website.
In This Article
What Is a Canonical Tag?
A canonical tag is a bit of HTML code that tells search engines which version of a page, among several duplicate or similar pages, to index.
Here’s what this HTML element looks like.
rel="canonical"And here’s what it looks like, combined with the canonical URL.
<link rel="canonical" href="https://example.com/example-page">The canonical tag is used when a site has more than 1 page with similar or duplicate content.
For example, imagine you have a site that sells t-shirts. One t-shirt style features Angry Birds characters. And there’s one main page displaying all the available Angry Birds t-shirts.
https://tshirts.com/angry-birds/But visitors can click to view different colors and styles, and when users click they get a different URL, but the content is almost exactly the same.
https://tshirts.com/angry-birds/redhttps://tshirts.com/angry-birds/red/hoodiehttps://tshirts.com/angry-birds/red/long-sleeveCheck to see if your site is using query arguments for these duplicate URLs. If so, you can use All in One SEO to easily manage those query arg URLs.
In this case, you’d pick the main Angry Birds page to be your “canonical” page, i.e., the one that gets indexed, because that’s where you want your prospects to ‘land.’
By selecting 1 page to be the canonical page, you avoid messy search results or duplicate content issues.
You’d want this code to be placed in the HTML for all the variants of the main Angry Birds t-shirt page.
<link rel="canonical" href="https://tshirts.com/angry-birds/">Where Is the Code Placed?
The canonical code is placed in the <head> section of the page’s HTML.
<html>
<head>
<title>Get Your Angry Bird T-Shirt!</title>
<link rel="canonical" href="https://tshirts.com/angry-birds/">
<!-- other elements -->
</head>
<!-- rest of the HTML →However, as you’ll soon see, there’s no need for site managers to deal with code. There are click-button ways of marking pages as canonical.
Before we get to that, let’s clear up the difference between canonical tags and canonical URLs.
Canonical Tags vs. Canonical URLS
Marketers often use “canonical tags” and “canonical URLs” interchangeably. That’s okay, but they are distinct things.
- We’ve defined canonical tag above.
- A canonical URL is simply the preferred URL that you associate the canonical tag with.
Understanding Canonicalization
Now, let’s cover a couple of key points about canonicalization.
That’s a big word but has a simple definition. Google defines canonicalization as the “process of selecting the representative –canonical– URL of a piece of content.”
Google also calls this process “de-duplication.”
De-Duplication
In addition to the Angry Birds ecommerce example above, another scenario where you might choose canonical pages is when your content management system automatically generates URLs that use tags or categories in their links.
An example of multiple URLs pointing to the same content include things like this.
A blog post URL which is:
https://mysite.com/how-to-use-a-sextantThen the site platform generates multiple URLs to that same post, by adding tags or categories to the URL, like:
https://mysite.com/maritime-navigation/how-to-use-a-sextant/https://mysite.com/celestial-navigation/how-to-use-a-sextant/Additionally, you may have duplicate content with URLs for various regions, like:
https://mysite.com/best-organic-cat-food/
https://mysite.uk/best-organic-cat-food/
Can Google Ignore Canonical Tags?
Next, it’s important to realize that canonical tags provide a hint to Google, but the search giant isn’t required to accept your choice of canonical page.
If their systems detect that a different page would be a better canonical, they may choose that page.
To understand their process better, let’s read how Google describes it:
If Google finds multiple pages that seem to be the same or the primary content very similar, it chooses the page that, based on the factors (or signals) the indexing process collected, is objectively the most complete and useful for search users, and marks it as canonical.
Among Google’s considerations are whether:
- The page URL is in a sitemap. (A weak signal.)
- You’ve added the canonical tag to the page. (A strong signal.)
Canonical Tags in SEO
Google makes clear that they evaluate the content and quality of only the canonical page, not the duplicate or similar pages.
Since quality is the #1 ranking factor, then choice of a canonical page can affect rankings.
In addition, the canonical page will be crawled more frequently than the duplicate pages. This can impact how quickly updates and changes to a canonical page display in search results.
It’s also important to know that, in cases of duplicate content, canonicals can make for a better user experience.
Instead of having to choose from a cluster of related pages on Google, users can clearly see which page they should click on.
Best Practices for Canonical Tags
Google has also provided the best practices for canonical tags.
One Canonical Per Page
This is common sense. It wouldn’t make sense to try to declare 2 or 3 pages to be the definitive page for Google to index.
That would be like the Western Schism, in the medieval era, when 3 men claimed to be pope!
Absolute, Not Relative URLs
When formatting canonical tags, this URL structure is to be used:
<link rel="canonical" href="https://mysite.com/organic-cat-food/"><link rel=”canonical” href=”https://mysite.com/organic-cat-food/“>
Not this:
<link rel="canonical" href="/organic-cat-food/">Use HTTPS
Every site should be using HTTPS. This signals that your site is safe for browsing.
HTTPS is made possible by adding an SSL certificate to your site. Ask your web host about this.
Specifically, request a Let’s Encrypt certificate: it’s free.
Use Lower Case
This:
<link rel="canonical" href="https://mysite.com/organic-cat-food/">Not this:
<link rel="canonical" href="https://MYSITE.COM/ORGANIC-CAT-FOOD/">Now, let’s look at how you can manage canonical tags with the All in One SEO (AIOSEO) plugin.
Managing Canonical Tags With AIOSEO
Creating a Custom Canonical URL
With All in One SEO, you can specify a canonical URL for any page.
First identify a set of duplicate pages and identify the one you want to be the canonical. Keep that URL handy.
Now, for each duplicate page, navigate to that page in the WordPress editor.
- Either select Advanced in the AIOSEO sidebar at right
- Or scroll to the bottom and click on the Advanced tab.
Then, next to Canonical URL, enter the full URL of the canonical page.
That’s it. There’s no need to set a Priority Score or to change the Robots Setting on the page.
Optimize Pagination
Next, you can use All in One SEO to optimize pagination.
Pagination refers to breaking up chronological listings of content (whether of products or articles) into multiple listing pages.
Most website platforms do this automatically.
For instance, if you have a blog on your WordPress site, you’ll notice, that the main /blog/ page lists all your posts.
As you add more posts, WordPress automatically adds another listing page.
Above: Example of pagination on the AIOSEO blog.
To prevent all these pages from seeming like duplicates to search engines, we can tweak them a bit.
Using AIOSEO to Optimize Pagination
To do this, in the WordPress editor navigation, go to AIOSEO » Search Appearance
Click on the Advanced tab.
Then scroll down to Paged Format.
This will add the page number to the title and description of those pages. This ensures that each page has a unique title and description.
So you’ll have Blog – Page 1, Blog – Page 2, and so on.
If you like, you can replace the word “Page” with something else, or add additional words like:
Blog – Article Listings: Page 1
Blog – Article Listings: Page 2
To learn more about optimizing pagination, watch our YouTube video.
Q&A on Canonical Tags
What’s the difference between canonical tags and redirects?
Canonical tags are used to indicate the preferred version of a page for search engines, while redirects are used to send users and search engines from one URL to another.
Both techniques help manage duplicate content and optimize search engine visibility, but they have different purposes, implementations, and effects on indexing, user experience, and link equity.
Purpose:
- Canonical Tags: Are used to specify the preferred (canonical) version of a web page when there are multiple pages with similar or duplicate content. They help search engines identify which URL should be considered the main version.
- Redirects: Are used to send users and search engines from one URL to another. They are typically used when a page has been permanently moved or deleted, or to consolidate multiple pages into one.
Implementation:
- Canonical Tags: Are implemented using the “<link rel=”canonical”>” element in the HTML head of a web page. They point to the preferred URL that should be indexed by search engines.
- Redirects: Are implemented on the server side, using HTTP status codes such as 301 (permanent redirect) or 302 (temporary redirect). They instruct the browser to navigate to a different URL.
- In WordPress, All in One SEO provides click-button ways to create canonical URLs and redirects.
Indexing:
- Canonical Tags: With canonical tags, search engines may still index and display the non-canonical versions of a page in search results, but they will attribute any ranking signals (like links) to the canonical URL.
- Redirects: When a redirect is in place, search engines will typically index only the destination URL, as they understand that the original URL has been permanently moved.
User Experience:
- Canonical Tags: Can provide a better user experience for, say, shoppers looking for a main product page, vs. a variant page displaying a certain color or style of a product.
- Redirects: Automatically send users to the new URL, providing a seamless experience and ensuring they land on the intended page.
Link Equity:
Redirects: Redirects pass link equity from the old URL to the new URL, helping to maintain the search engine rankings of the content.
Canonical Tags: Help consolidate link equity (also called link juice) from multiple URLs to the canonical URL. Earned backlinks will point to the canonical URL.
Should I use canonical tags?
Canonical tags can be helpful in avoiding duplicate content issues that might otherwise confuse users. They can also be useful in optimizing pagination.
However, keep in mind that Google advises, “your site will likely do just fine without specifying a canonical preference. That's because if you don't specify a canonical URL, Google will identify which version of the URL is objectively the best version to show to users in Search.”
After Canonical Tags
Now that you’ve learned what canonical tags are and how to use them, what’s next?
- Learn how to manage query args with All in One SEO. This is related to duplicate content present on many ecommerce sites.
- Explore 4 schema types that can boost your ecommerce site.
- And be sure to have lead magnets in place and mobile-friendly forms. That way, your SEO results will be maximized.
Join us on our YouTube Channel for SEO tutorials. And follow us on X (Twitter), LinkedIn, or Facebook to stay in the loop.
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