URL Canonicalization

What is URL Canonicalization?

URL canonicalization is the process of selecting the representative –canonical– URL of a piece of content. Consequently, a canonical URL is the URL of a page that Google chose as the most representative of a set of duplicate pages. Often called deduplication, this process helps Google show only one version of the otherwise duplicate content in its search results.

What is the difference between a URL and a canonical URL?

A URL (Uniform Resource Locator) is the address that specifies the location of a resource on the internet. In contrast, a canonical URL is a specific type of URL used to indicate the preferred version of a web page when duplicate content exists. 

Examples of a canonical URL (show code or screenshots)

A popular example of canonical URLs can be most commonly seen in eCommerce sites. For example, consider you have an eCommerce site; abc.com and you sell dresses in different colors. 

So, in this case:

    • Canonical URL: https://abc.com/dresses/
    • Alternate URL: https://abc.com/dresses/blue/

In most cases, Google selects the canonical URL; however, you can influence Google’s decision by using canonical tags. Consider the screenshot below:

URL Canonicalization issue in google search console

Why does canonicalization matter in SEO?

Here are some of the most important benefits of canonicalization and why they matter in SEO: 

    • The canonical tag helps suggest to Google the best version of a page on your website that you want to provide to users.
    • Google uses the canonical tag to determine the content and quality of a page. It relies on the canonical URL to understand which version should be indexed and displayed in search results.
    • The canonical version of a page is crawled more frequently by Google compared to non-canonical versions. This can help with optimizing the crawl budget, which refers to the resources allocated by search engines for crawling and indexing web pages.
    • Canonical tags are not a replacement for other directives like no-index tags, redirects, or robot directives. Each of these directives serves different purposes and should be used appropriately based on the specific requirements.
    • By using canonical tags, search engines consolidate the link signals from similar pages into a single URL, increasing its value in terms of search engine rankings and authority.
    • If your website syndicates its content for publication or is utilized by partners, using canonical tags ensures that your preferred version of the content appears in search results, giving you control over how your content is displayed.
Related SEO glossary terms
301 Redirects Guest Blogging
302-redirect H1 tags
404-page Impressions Ranking Positions
Alt tag Indexing
Anchor text Keyword Clustering
Backlinks Keyword Difficulty
Black hat SEO Meta Description
Bounce Rate Meta Tags
Breadcrumb Navigation No follow Link
Canonical Tag Offpage SEO
Content Hub On Page SEO
Core algorithm updates Orphan Pages
Core Algorithm Updates Page Title
Core Web Vitals PageRank
Crawl Budget Robots.txt
CTR Schema Markup
Do Follow Link Search Engine
Domain rating Search intent
Duplicate page Search volume
External Links SERP
Google Knowledge Graph Sitemap
Google Knowledge Panel Technical SEO
Google Search Console Topic Authority
Google Search Console URL Canonicalization
Google Webmaster Guidelines Web crawler
  Website traffic