Canonical tag

Why it matters

The canonical tag tells search engines which URL is the preferred version of a page. Without it, or with a wrong one, duplicate URLs (with parameters, http/https, www) can split signals or the wrong page can be indexed.

How to fix it

1. Add <link rel="canonical" href="…"> with the full preferred URL on every indexable page.
2. Point it at the page itself unless the page is a true duplicate.
3. Use only one canonical tag, and keep it the same in the raw HTML and after JavaScript runs.

Check it with

• Canonical Tag Checker – Check a page’s canonical URL, whether it resolves, and if it conflicts with other signals.

Scoring: a passed check earns its full weight, a warning half and an error none. How the SEO score works

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