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Canonical Tag Checker

Detect missing canonical tags, trailing spaces, protocol mismatches, and www issues that confuse Google. Instant results — no signup.

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Canonical Health Score

🔗 Canonical Tag Found

⚠️ Issues Detected

    📊 Canonical Details

    🏷️ Other SEO Tags (Snapshot)

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    Why Canonical Tags Break (and Why It Matters)

    A broken canonical tag is one of the most silent SEO killers — it won't throw a 404, but Google may quietly deindex your best pages.

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    Trailing Space Bug

    A single extra space in href="https://example.com " makes the canonical technically invalid. Common in CMS exports and Webflow. Google may ignore it entirely.

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    www vs Non-www Mismatch

    If your site serves on www.example.com but your canonical says example.com, Google sees conflicting signals and may choose the wrong version.

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    HTTP vs HTTPS

    Canonical pointing to http:// when your site is on https:// tells Google the old HTTP version is the authoritative page — the opposite of what you want.

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    Missing Canonical Entirely

    Without a canonical tag, Google has to guess which URL version to index. If your page is accessible at multiple URLs, you're splitting your ranking signals.

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    Cross-Domain Canonical

    A canonical pointing to a completely different domain tells Google your content is a copy of someone else's page — devastating for rankings on that page.

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    Multiple Canonical Tags

    Having two <link rel="canonical"> tags on the same page sends conflicting signals. Google will typically use the first one or ignore both.

    Frequently Asked Questions

    A canonical tag (rel=canonical) tells search engines which URL is the authoritative version of a page. Without it, Google may index multiple versions of the same content — with and without www, with and without trailing slashes, or with URL parameters — splitting your ranking power across duplicates. Every page should have exactly one canonical URL.

    Common canonical tag issues include: (1) Missing canonical tag entirely — Google has to guess; (2) Trailing space in the href value — technically invalid and browsers may not resolve it correctly; (3) Canonical pointing to a different domain, subdomain, or protocol; (4) Relative canonical URL that resolves incorrectly; (5) Self-referencing canonical not matching the actual page URL; (6) Multiple canonical tags on the same page.

    A canonical tag is a hint to search engines about which URL is preferred — it doesn't move users or browsers anywhere. A redirect (301/302) actually sends both users and search engines to a new URL. For duplicate content, a canonical tag is preferred when you want the original URL to remain accessible. Use a 301 redirect when the old URL should never be visited directly.

    Yes, in most cases a page's canonical tag should point to itself (self-referencing canonical). The URL in the canonical should use the correct protocol (https), subdomain (www or non-www as your preference), and path. Mismatches — even small ones like a trailing space or extra slash — can cause Google to ignore the canonical signal.

    Add a self-referencing canonical to every page's <head>: <link rel="canonical" href="https://yourdomain.com/exact-page-url">. Make sure the href value has no trailing spaces, uses https, and matches your preferred www/non-www format exactly. In Webflow, use the built-in Canonical URL field. In WordPress, install Yoast SEO or Rank Math which handle this automatically.