TL;DR: What is a Canonical URL?

A canonical URL is the URL of the best representative page from a group of duplicate pages, according to Google. For example, if you have two URLs for the same page (such as example.com? dress=1234 and example.com/dresses/1234 ), Google chooses one as canonical.

Similarly, if you have multiple pages that are nearly identical, Google can group them together (for example, pages that differ only by the sorting or filtering of the contents, such as by price or item color) and choose one as canonical. Google can only index the canonical URL from a set of duplicate pages.” Source

Why Should You Use Canonical URLs?

Using canonical URLs is essential for several reasons, primarily related to SEO and content syndication. Here are some of the primary reasons:

Consolidating Link Signals for Similar or Duplicate Pages

Search engines often use the number and quality of backlinks a page has to determine its ranking. When multiple pages with similar content exist, the link signals can get diluted as different backlinks might point to different versions of the same content. By using a canonical URL, you consolidate these link signals, ensuring that the preferred version of the page gets the combined link signals of all its variants.

Managing Syndicated Content

If you syndicate your content for publication on other websites, you can use canonical URLs to ensure that the search engines understand where the original version resides. This way, the syndicated content won't compete with your original content in search engine results.

Specifying Preferred URLs for Search Results

Sometimes, you might have slight variations of a page for tracking or A/B testing purposes. By setting a canonical URL, you can specify which version of the page you want to appear in search results.

How to Properly Use Canonical Tags

Using canonical tags correctly is crucial for ensuring that search engines understand your preferred version of a page. Here's a step-by-step guide on how to do it right:

Selecting the Correct Canonical URL

Before implementing a canonical tag, you need to decide which URL is the "canonical" one. This should be the most authoritative version of the page. Consider factors like:

  • Which version has the most backlinks?
  • Which version has the most user engagement or traffic?
  • Which version aligns best with your site's structure and navigation?

Implementing Canonical Tags in Different Platforms

Different platforms have various methods for adding canonical tags. Here's a brief overview of how to do it on some popular platforms:

Magento 1

Product Page Canonicals

  • Navigate to System > Configuration > Catalog > Search Engine Optimizations.
  • Set Use Canonical Link Meta Tag For Products to "Yes".

Category Canonicals

  • Navigate to System > Configuration > Catalog > Search Engine Optimizations.
  • Set Use Canonical Link Meta Tag For Categories to "Yes".

Magento 2

In Magento 2, the process is streamlined. Simply navigate to Stores > Configuration > Catalog > Catalog > Search Engine Optimization and enable the canonical options for both products and categories.

WordPress

Yoast SEO Plugin

  • Go to SEO > Search Appearance.
  • Under the 'Content Types' tab, ensure that the 'Show SEO settings for [Content Type]' is set to "Yes".
  • Below, you'll find the option to enable canonical URLs.

Rank Math SEO Plugin

  • Navigate to Rank Math > Titles & Meta.
  • Choose the content type you want to set the canonical for.
  • Scroll down to find the canonical URL option and set it.

Wix

In Wix, you can set canonical URLs using the SEO settings for each page. Simply navigate to the page's settings, find the SEO section, and input your preferred canonical URL.

Canonical Tags: SEO Best Practices

When implementing canonical tags, it's essential to follow best practices to ensure that search engines correctly interpret your intentions. Here are some key guidelines to keep in mind:

  • Only Specify One Canonical URL Per Page. Ensure that each page has only one canonical tag. Multiple canonical tags can confuse search engines and lead to unpredictable results.
  • Specify the Correct Domain Protocol. Always be consistent with the domain protocol. If your website uses HTTPS, ensure that the canonical URL also uses HTTPS. Mixing HTTP and HTTPS can lead to duplicate content issues.
  • Specify Trailing Slash or Non-Trailing Slash URLs. URLs can be written with or without a trailing slash (e.g., example.com/page vs. example.com/page/). Decide on one format and stick to it consistently across your canonical tags.
  • Specify Non-WWW or WWW URLs. Just like with trailing slashes, decide whether you want to use the www subdomain in your canonical URLs. Once you've made a decision, be consistent across all pages.
  • Use Absolute URLs. Always use absolute URLs (e.g., https://www.example.com/page) instead of relative URLs (/page). Absolute URLs leave no room for ambiguity, ensuring that search engines understand the exact page you're referencing.
  • Never Point Canonical Tags to Redirected Pages. Ensure that the canonical URL you specify does not redirect to another page. This can confuse search engines and dilute the effectiveness of the canonical tag.
  • Only Use Canonical Tags for Duplicate Content. Canonical tags should only be used for pages with duplicate or very similar content. Using them on unique pages can lead to those pages being ignored by search engines.

How to Audit Canonical Tags on Your Site

A thorough audit can help identify potential issues that might be affecting your site's SEO. Here's what to look for during your audit:

Number of Pages with Duplicate Content Issues

One of the primary reasons for using canonical tags is to address duplicate content issues. Start your audit by identifying pages with similar or identical content. Tools like Screaming Frog or SEMrush can help you spot these duplicates.

Number of Pages with Multiple Canonical URLs

Having multiple canonical tags on a single page can confuse search engines. Ensure that each page on your site specifies only one canonical URL. SEO tools like Screaming Frog can help you identify such issues.

Number of Pages with a Broken Canonical Link

A canonical tag that points to a non-existent or broken URL is counterproductive. Ensure that all canonical URLs are accessible and return a 200 OK status. Tools like Ahrefs or Moz can help you identify and fix broken canonical links.

Number of AMP Pages Without a Canonical Tag

If your site uses Accelerated Mobile Pages (AMP), it's essential to have a canonical tag pointing from the AMP version to the standard version of the page. This ensures that search engines understand the relationship between the two and can consolidate ranking signals.

Auditing canonical tags might seem like a daunting task, but with the right tools and a systematic approach, it becomes manageable. Regular audits ensure that your canonical tags remain effective and continue to support your site's SEO efforts.

Conclusion

Canonical URLs help search engines understand which version of a page is the most authoritative, ensuring that your content gets the visibility it deserves. By following best practices and regularly auditing your canonical tags, you can avoid common pitfalls and ensure that your website remains in good standing with search engines.

FAQ

What is a canonical URL?

A canonical URL is a way of telling search engines that a specific URL represents the master copy of a page. It helps search engines understand which version of a page to index and rank, preventing issues related to duplicate content.

Why are canonical URLs important for SEO?

Canonical URLs help prevent duplicate content issues, which can dilute the ranking power of a page. By specifying a canonical URL, you consolidate ranking signals to a single, authoritative version of the page, improving its chances of ranking higher in search results.

How do canonical URLs affect website traffic?

By consolidating ranking signals and preventing duplicate content issues, canonical URLs can help improve a page's search ranking. Higher rankings typically lead to increased organic traffic.

Can I have multiple canonical URLs for a single page?

No, each page should have only one canonical URL. Having multiple canonical tags can confuse search engines and lead to unpredictable indexing and ranking results.

How do I choose the right canonical URL for a page?

The canonical URL should be the most authoritative version of the page. Consider factors like user engagement, backlinks, alignment with site structure, and overall importance to your website's goals.

Are canonical URLs necessary for every page on my website?

Not necessarily. Canonical URLs are primarily used for pages with duplicate or very similar content. If your website doesn't have such issues, you might not need to use canonical tags extensively.

How often should I audit my website's canonical URLs?

Regular audits, at least annually or after significant website changes, are recommended. This ensures that your canonical tags remain effective and continue to support your site's SEO efforts.

When would you use a canonical vs. a 301 redirect for duplicate content?

If the duplicate page serves no SEO or user value on the site, it is best recommended to remove and 301 redirect to an active/similar page with value. In most other cases, a canonical tag will be the ideal choice.