Canonical tag

What is a canonical tag?

A canonical tag (rel="canonical") is an HTML element placed in the <head> of a page. It tells search engines which URL is the preferred, or canonical, version when the same or very similar content is reachable at several addresses. Search engines then group the duplicates and concentrate ranking signals, such as links, on the chosen URL instead of splitting them.

It is a hint, not a command. Google usually follows it, but may pick another URL if other signals disagree.

How it works and syntax

The tag sits in the head of every duplicate or variant page and points to the preferred URL:

<link rel="canonical" href="https://www.example.com/shoes/" />

• Use an absolute URL with protocol and domain, not a relative path.
• The preferred page should carry a self-referencing canonical that points to itself.
• The tag can also be sent as an HTTP header, which is useful for PDFs and other non-HTML files.

When to use it

• URL parameters: tracking codes, filters and sort orders that create many addresses for one page.
• Protocol and host variants: http versus https, with or without www.
• Similar pages: product variants, print versions or syndicated articles.
• Pagination and campaigns: landing page copies that differ only slightly.

Canonical tag versus other signals

Best practices and common mistakes

• Point to a page that returns a 200 status, never to a redirect, an error page or a noindexed URL.
• Do not chain canonicals, where A points to B and B points to C.
• Keep one canonical per page. Conflicting tags make search engines ignore both.
• Align the canonical with your sitemap, internal links and redirects so every signal agrees.
• Do not canonicalise paginated pages to page one, since this hides the content of later pages.
• Audit with a crawler to spot missing, duplicated or non-matching canonicals.

Canonical tags, indexing and crawl budget

Clean canonicals reduce duplicate content, help indexing choose the right URL and save crawl budget on large sites. They work alongside a 301 redirect, a noindex directive and an accurate sitemap.

Canonical tags at BeBranded

At BeBranded, we set canonical rules during the technical audit and build them into the site template, so every page and CMS item declares the right URL from day one. We then check them against redirects and the sitemap after each release. It is a routine part of our SEO and GEO service.