What is a canonical URL?
What a canonical URL is, how Google picks one, and how to point it
A canonical URL is the URL Google picks as the most representative page from a set of duplicate or very similar pages, and it's the one Google usually shows in search results. You can state a preference with redirects, a rel="canonical" link or your sitemap, but Google treats that preference as a hint, not a rule. Most sites do fine without setting one, though setting one helps combine links and makes performance easier to track.
What it is
When the same content is reachable at more than one address, Google groups those pages and picks one to represent the group. That pick is the canonical URL. Google calls the process canonicalization and says it's often called deduplication. It lets Google show one version of the content in results instead of several.
Duplicates are common, and there are many reasons a site can have them. Google lists separate US and UK pages in the same language, mobile and desktop versions, HTTP and HTTPS copies, sorted and filtered category pages, and demo sites left open to crawlers. Some duplication is normal and isn't a spam policy problem.
How Google chooses
Google works out the main content of each page, groups pages whose main content looks the same, and marks the one it judges most complete and useful for searchers as canonical. The signals include whether a page uses HTTPS, redirects, sitemap inclusion and rel="canonical" links.
Google can overrule you. Its documentation says a canonical preference is a hint, not a rule. The canonical page is crawled most often and becomes the main source for judging content and quality. Results usually point to it, unless a duplicate suits the searcher better, such as a mobile page for someone on a phone.
How to state a preference
Google ranks the methods by strength. A redirect is a strong signal that its target should be canonical. A rel="canonical" link is also strong. Including a URL in a sitemap is weak. Using two or more together raises the chance your preferred URL shows in results.
Keep the signals consistent. Don't name one URL in the sitemap and a different one in rel="canonical" for the same page. Put a rel="canonical" pointing to itself on the canonical page, link to the canonical URL within your site, and don't name a URL fragment as canonical. If you use a CMS such as WordPress, Wix or Blogger, look for a search engine settings page instead of editing HTML.
What not to use
Google says not to use robots.txt for canonicalization, because a disallowed URL can still be indexed without its content. The URL removal tool hides every version of a URL from Search, so it's the wrong tool too. Google also doesn't recommend noindex for choosing a canonical within one site, because it blocks the page from Search entirely.
Sources
- developers.google.com/search/docs/crawling-indexing/canonicalization
- developers.google.com/search/docs/crawling-indexing/consolidate-duplicate-urls
Each was read on October 11, 2026.
Questions
Do I need to set a canonical URL?
No. Google says none of the methods are required and most sites will likely do fine, because Google picks the best version itself. Setting one helps control which URL people see, combine link signals and simplify tracking.
Will Google always use the canonical I set?
Not always. Google treats rel="canonical", redirects and sitemaps as hints, and it may choose a different page for its own reasons.
Should a page point rel="canonical" at itself?
Yes. Google's best practices say to include a rel="canonical" link on the canonical page itself, known as a self-referential canonical.
Work with us
Let the agents bring you the leads.
Tell us about your business and who buys from you. On a short call we'll show you the searches your buyers make where you don't show up yet, and what the agents would do about them in their first month.
On the call, for your site
- The searches your buyers makeMeasured, with how many people make each one
- Where you show up, and where you don'tOn Google and in ChatGPT's answers
- The agents' first monthThe pages, fixes and links they would start with