Why this matters
A rel=canonical tag tells Google which URL is the definitive version of a page. Without
one, Google performs its own canonicalisation — selecting whichever URL it considers the
primary version. It often gets this right, but not always. Duplicate URLs (with and without
trailing slashes, http vs https, or query strings) can split crawl equity and cause the
wrong URL to rank.
Run the free Meta Tag Analyzer to see every tag, its length verdict, and exactly what to fix.
How to check
Paste your URL into the Meta Tag Analyzer. It shows whether a canonical tag is present, whether the URL is absolute, and whether the canonical points back to the same page.
How to fix
- Add a
<link rel="canonical" href="https://yourdomain.com/the-page/">to the page<head>. - Make the URL absolute — include the scheme and domain, not just the path.
- Confirm the canonical URL returns 200 — a canonical pointing to a redirect or 404 is treated as invalid.
- Make sure each page has exactly one canonical tag; multiple canonicals on one page are ignored.
Example
A self-referencing canonical on https://example.com/products/widget:
<link rel="canonical" href="https://example.com/products/widget" />This tells Google the exact URL to index. Keep it consistent with any <loc> entries in
your sitemap. See Canonical tags explained for a full
breakdown.