SEO, Technical SEO

What Are Canonical Links and Why Are They Important for SEO?

Canonical links, also known as canonical tags, are an component of SEO for managing duplicate content and ensuring search engines understand which version of a page is the most important. If you’re serious about improving your site’s SEO and willing to dive deep into Technical SEO, understanding canonical links is crucial.

What is a Canonical Link?

A canonical link (or tag) is an HTML element that tells search engines which version of a URL is the preferred or “canonical” one. In simpler terms, it helps prevent duplicate content issues by specifying the main version of a page when there are multiple URLs with the same or similar content.

For example, if you have a product page accessible via multiple URLs (e.g., with and without tracking parameters), a canonical tag can point search engines to the preferred URL, ensuring all SEO benefits are directed to that page.

How and Where is it Added?

Canonical links are added within the <head> section of your website’s HTML. The tag looks like this:

<link rel="canonical" href="https://example.com/preferred-page-url/" />
HTML source code for a website showing the canonical tag.

This tag should be placed on every page that has variations or duplicates, specifying which version search engines should prioritize.

Most content management systems (CMS), like WordPress or Shopify, have built-in options to set canonical tags automatically, but they can also be added manually in your site’s code.

How Do Google and Search Engines Use Canonical Links?

When search engines like Google crawl your site, they come across many different URLs. If multiple pages contain similar or duplicate content, Google might have trouble deciding which page should appear in search results. A common example of this is if the webserver will serve the website on both the main ‘root domain’ and the ‘www’ subdomain which would result in a duplicate website.

Canonical tags help guide search engines by pointing them to the preferred version of a page and website.

When a canonical tag is present, search engines will index and rank the URL specified in the tag while ignoring the other duplicates. This ensures that your preferred URL gets the SEO credit and appears in search results.

Screenshot of Google Search Console showing the detected 'user-declared canonical' for a page

The above picture shows Google Search Console detecting the HTML ‘user-declared canonical’ tag within a particular web-page instructing the search engine that ‘https://iptools.net.au/cubic-weight’ is the primary page, and not any variations like ‘https://www.iptools.net.au/cubic-weight’

Picture showing Google Search console not detecting a user-declared canonical tag.

If a ‘canonical tag’ is not supplied, as shown by the above picture, Google can often make an educated guess as to what the page should be, however it is not always correct.

Why Are Canonical Links Important?

Prevents Duplicate Content Issues: Duplicate content can confuse search engines, leading them to index the wrong page, split ranking signals between multiple versions of the same page or simply not index the page. Canonical links consolidate these signals and prevent such issues.

Consolidates Link Equity: If different URLs point to the same content, the link equity (SEO value) might be split. Canonical tags ensure that all the ranking power is directed toward the preferred page.

Improves User Experience: By guiding search engines to the right page, you ensure users land on the correct version of your content, reducing confusion, bounce rate and improving their experience.

Boosts SEO: Ultimately, canonical links help make sure the right pages rank in search results, boosting your overall SEO efforts.

Wrap Up

Canonical links are a small but crucial part of any SEO strategy. They help search engines understand which page to prioritize, prevent duplicate content issues, and ensure you are getting the most out of your SEO efforts.

If you need assistance with Canonical Links on your own site, SEO Hawk offers affordable Technical SEO services