Short definition

Canonical URL — the preferred page URL declared in a canonical link when the same or very similar content is available at multiple addresses.

Also known as: rel="canonical", canonical link.

A canonical URL helps search engines consolidate signals from duplicate or near-identical URLs. The page declares its preferred address in a link element in the document head.

How does a canonical URL work?

Canonicals are a strong signal, but not an absolute command. Internal links and sitemap entries should use the preferred URL, and redirects should lead to it. If a page has moved permanently, a redirect is usually clearer. Search engines may ignore a canonical that points to substantially different content.

What does this mean for a small business?

Duplicate URLs arise from parameters, filters, print versions, old routes, or variants with and without a trailing slash. The simplest approach for a small site is consistency: one public URL per page and permanent redirects for old addresses. Always check the generated HTML after a migration.

How should you configure canonical URLs?

  • use absolute, correctly formed preferred URLs;
  • make every indexable page point either to itself or to a page with matching main content;
  • keep sitemap entries and internal links aligned with the canonical;
  • use redirects for URL variants that should no longer be accessible;

How it relates to other website choices

A canonical supports SEO. The page URL used in structured data should match it. A canonical does not repair content that was unintentionally copied onto multiple standalone pages.