seo/canonical-valid

Why

The canonical tells search engines which of several URLs with the same content to show (with and without parameters, trailing slash, www). Two canonicals, a relative path resolved against the wrong base, or a fragment make search engines ignore the hint and pick one themselves.

Fix

Emit one <link rel="canonical" href="https://example.com/path"> per page from the layout, built from the site's configured origin and the clean path (no tracking parameters, no #). Point it at a page that returns 200 and is not noindex. Keep sitemap URLs equal to canonical URLs.

Examples

<!-- bad -->
<link rel="canonical" href="/pricing">
<!-- good -->
<link rel="canonical" href="https://example.com/pricing">

Sources

• Chrome for Developers, Document does not have a valid rel=canonical (Lighthouse audit)

Read it in the terminal

npx github:dawidolko/frontend-skills explain seo/canonical-valid