Canonical Tags for Local Sites: A Practical Guide

Canonical tags tell search engines which URL is the preferred version of a page. They prevent duplicate-content issues when the same content is accessible at multiple URLs. This guide covers canonical tags for local sites. See Technical SEO Audit for the broader context.

Self-referencing canonicals

Every page should have a self-referencing canonical tag pointing to its own preferred URL. This is the default. Google documents canonicalization in Search Central.

When canonicals matter

• Parameterized URLs (e.g., ?sort=price, ?page=2) — canonicalize to the clean URL.
• HTTP vs. HTTPS — canonicalize to HTTPS.
• www vs. non-www — canonicalize to the preferred host.
• Trailing slash vs. no trailing slash — canonicalize to the preferred format.
• Syndicated or cross-posted content — canonicalize to the original.

Common mistakes

• Pointing the canonical to a different page by accident (e.g., a template error).
• Canonicalizing paginated pages to the first page (use rel=prev/next or self-referencing instead).
• Canonicalizing to a URL that returns a 404 or redirect.
• Conflicting canonicals (HTTP header says one thing, HTML tag says another).