What is a canonical URL?
A canonical URL (rel=canonical) tells Google which version of a page is preferred when there's similar or duplicate content.
When to use canonical
Pages with tracking parameters (?utm_source=...), print versions, syndicated content, www vs non-www URLs, and HTTP vs HTTPS versions.
How to implement
<link rel="canonical" href="https://example.com/article/" />
Place the tag in the non-canonical page's head pointing to the canonical one.
Best practices
Use absolute URLs (not relative), one canonical per page, ensure the canonical is accessible (not 404).
Common errors
Canonical loops (A points to B and B points to A), non-indexable canonical, and long canonical chains.
Canonical vs 301 redirect
301 permanently redirects user and bot. Canonical only affects search engines. Use 301 for pages that shouldn't exist.
Conclusion
Canonical URLs protect your SEO from duplicate content. At Vynta we implement canonicalization strategies that consolidate authority on your main pages.