Canonical links – what are they and how do you use them?
9.10.2026
SEO
Glossary
A canonical link is an SEO tool that helps manage duplicate content within a single website. In this article we explain what a canonical link actually is, what it is used for and why implementing it correctly is crucial to optimising a site for search engines.
What is a canonical link?
A canonical link is a specific URL identifying the most representative, main version of a page where several versions of the same or very similar content exist. It is defined with a canonical tag (rel="canonical") placed in the <head> section of the page's HTML. That tag tells search engine crawlers which version of the page should be indexed and treated as the original.
An example of using a canonical link
Imagine we have a website plus different versions of the same page with additional parameters, such as UTM tags for tracking marketing campaigns:
To avoid Google indexing both addresses, we can use a canonical link pointing at the version without parameters:
"<link rel="canonical" href="https://example.com/" />"
That way search engine crawlers will index only one main URL, avoiding duplicate content problems.
The canonical tag plays a key role in a search optimisation strategy, because using it correctly affects several important aspects of a site. Here is a more detailed explanation:
- Managing duplicate content:
- Duplicate content can take various forms, e.g. when different URLs lead to the same or very similar content. Search engine crawlers may treat this as an attempt to manipulate rankings, which can result in penalties for the site.
- The canonical tag helps state unambiguously which version of the content is the original and should be indexed. That avoids duplication problems that can hurt a site's visibility in search results.
- Optimising crawl budget:
- Crawl budget is the number of pages Googlebot can index during one visit to your site. If crawlers waste time indexing duplicates, fewer resources are left for indexing new and unique content.
- The canonical tag indicates which pages are most important, letting crawlers use the crawl budget more effectively by focusing on the content of greatest value to users and search engines.
- Consolidating ranking signals:
- Where several versions of the same page exist, backlinks – one of the most important ranking factors – can be scattered across different URLs. That dispersion weakens the SEO authority the page could gain.
- Using a canonical tag consolidates those ranking signals, directing the full value of the backlinks to a single main URL. That gives the page greater authority, which can translate into a higher position in search results.
- Improving user experience:
- Consistent, clear URLs make for a better user experience. If users see different versions of the same page, they can be confused, which reduces their trust in the site.
- Canonical URLs help maintain a clear site structure, which benefits both users and search engine crawlers. Users have easier access to the original content, which improves their experience and increases the likelihood of a return visit.
- Preventing indexing problems with different language versions:
- On multilingual sites there is a risk that different language versions may be treated as duplicates. A canonical tag can help index content in different languages correctly, directing crawlers to the main version of the page.
- In addition, using hreflang tags alongside canonical URLs ensures the right language versions are presented to the right users in different markets.
- Preventing problems with dynamic URLs:
- On sites where dynamic URLs are generated by filtering and sorting systems, a canonical tag can prevent hundreds of unnecessary URL versions from being indexed.
- That lets search engines focus on indexing the important pages, improving the site's overall SEO performance.
Canonical links are an essential tool in an SEO strategy, helping manage content and ensure pages are indexed correctly. Here are the situations in which canonical links are worth using in detail:
- Filtering and sorting pages in online stores:
- Online stores often offer various product filtering and sorting options, generating many unique URLs for the same product category. Every filter or sort choice creates a new URL that search engines may index.
- To avoid duplicate content problems and wasted crawl budget, the canonical link should point at the main category page. That way Google and other search engines understand that all those dynamically generated pages are variants of one base page.
- Repeated product descriptions:
- In many online stores different products have very similar or even identical descriptions. That is particularly problematic for products differing only in small features such as colour or size.
- In such cases it is worth using a canonical link pointing at the most representative version of the product page. That focuses SEO authority on one page instead of scattering it across many duplicates.
- Similar blog posts:
- Blogs often contain posts on closely related topics that may have very similar content. For example, different articles may cover the same issue from a slightly different angle.
- To avoid duplicate content problems, you can use a canonical link pointing at the most developed and popular post on the topic. That tells search engines which article to index as the main one.
- Multiple URL versions:
- Websites can be available under different URL versions, such as with and without the "www" prefix, or with "http" and "https". Although a 301 redirect is the best solution in such cases, it is not always possible.
- In those situations you can use canonical links to tell search engines the preferred URL version. That helps consolidate SEO value and ensures only one version of the page is indexed.
- In addition, using hreflang tags alongside canonical URLs can help direct users to the right language versions of the site.
- Archive pages:
- Blogs and news sites often have archive pages containing older posts. These pages can be very similar to each other in content, which can lead to duplication problems.
- In such cases a canonical link can be used to point at the main archive page or the page with the most current information, ensuring older, less valuable pages do not compete for indexing.
How do you set canonical links?
Setting canonical links is usually simple and can be done in several ways:
- Through a content management system (CMS):
- Many popular CMS platforms, such as WordPress, offer plugins (e.g. Yoast SEO) that make it easy to add canonical links while editing a page.
- Adding it manually in the HTML:
- If you do not use a CMS, a canonical link can be added directly in the page's HTML in the <head> section:
"<link rel="canonical" href="https://www.example-site.com/" />"
Monitoring canonical links
To make sure canonical links are set correctly and respected by search engines, it is worth checking reports in Google Search Console regularly. The tool lets you monitor a site's indexing status and flags any problems with canonical URLs.
Summary
Canonical links are an essential element of SEO, helping manage duplicate content and improve how search engines index pages. Setting canonical URLs correctly is simple, and doing so can bring significant benefits to a site's visibility and ranking in search results. Regular monitoring and optimisation of canonical links is key to maintaining a healthy site structure and maximising its SEO potential.
Quick links
Related articles
10.9.2026
SEO in Bing – discover the power of effective optimisation in Microsoft's search engine, worth backing today
Read the full insightTIME FOR THE NEXT STEP
CONTACT US
Do you have a store, service, or brand you want to genuinely grow online?
Head over to our simple contact form and let us know what you need today.
We will get back to you with a concrete proposal for next steps and a time for a brief call.