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Canonical Tag Checker

Check canonical URL presence, self-referencing, absolute vs relative, and verify the canonical target returns 200.

Canonical Tag CheckerGratisOn-Page SEOChecks a live URL

Enter a public URL. We fetch the live page and analyse what search engines and AI crawlers see.

Key features of the canonical tag checker

  • Detects presence or absence of canonical tag in page head
  • Validates that canonical URL matches the expected page URL
  • Identifies self-referencing canonicals vs. canonical to another page
  • Checks for multiple canonical tags (invalid — only one is allowed)
  • Flags HTTP to HTTPS canonical mismatches

How to use the canonical tag checker

  1. Enter the page URL

    Paste the URL of the page you want to check into the canonical checker.

  2. Run the check

    Click 'Check Canonical Tag' to fetch the page and extract canonical tag data.

  3. Review canonical status

    See whether a canonical tag is present, its current value, and whether it's valid.

  4. Check for issues

    Look for missing tags, wrong canonical URLs, HTTP/HTTPS mismatches, or multiple canonicals.

  5. Implement fixes

    Add or correct the canonical tag in your CMS or theme, then re-run to verify.

What is a canonical tag checker?

The Canonical Tag Checker verifies the canonical URL tag (rel="canonical") on any webpage. It checks whether the tag is present, whether it's self-referencing (pointing to the page itself), whether it conflicts with other signals, and whether it's correctly implemented in the HTML head section.

Canonical tags are essential for preventing duplicate content issues. When multiple URLs serve similar or identical content (e.g., with/without www, HTTP/HTTPS, pagination, tracking parameters), the canonical tag tells search engines which version is the "master" copy that should be indexed and receive link equity.

Why use a canonical tag checker?

Without correct canonical tags, search engines may index duplicate versions of your pages, split link equity across multiple URLs, and choose the wrong version to rank. This can significantly dilute your SEO efforts. The canonical tag is one of the most powerful and most commonly misconfigured on-page SEO elements.

Canonical tag checker: frequently asked questions

Something else? Ask the team

What is a canonical tag?

A canonical tag is an HTML element (<link rel='canonical' href='...'>) placed in the page's <head> that tells search engines which URL is the preferred version of a page, preventing duplicate content issues.

When should I use a canonical tag?

Use canonical tags whenever the same or very similar content is accessible at multiple URLs — such as with/without www, HTTP vs HTTPS, URL parameters (e.g., ?sort=price), or paginated versions.

What is a self-referencing canonical?

A self-referencing canonical is when a page's canonical tag points to its own URL. This is recommended best practice for original pages — it explicitly confirms to Google that this URL is the definitive version.

Can canonical tags pass link equity?

Yes. When you canonicalise a duplicate page to the original, link equity (PageRank) from the duplicate flows to the canonical URL, consolidating ranking power.

What if I have both a canonical and a noindex tag?

Having both is contradictory. Noindex says 'don't index this page' while canonical says 'treat this as the master copy'. Google will typically respect noindex and ignore the canonical, which is usually not what you intend.

Each one opens on its own page and works straight away, with no sign-up.

Explorar más herramientas gratuitas:Generador de SchemaGenerador de etiquetas MetaGenerador de LLMs.txtBrowse all free tools

¿Quieres conseguir más menciones en la IA?

Canonical Tag Checker is one piece of the puzzle. See how ChatGPT, Gemini, Perplexity, and Google AI Overviews actually view your brand, and get a prioritised list of fixes, with a free AEO & GEO audit from AI Rank Lab.

One check is a start. The audit checks the whole site.

Realizar una auditoría AEO y GEO gratuita or Ver precios.

  • Scores SEO, answer-engine (AEO) and generative-engine (GEO) readiness
  • Lists the fixes, page by page
  • Then track whether ChatGPT, Gemini, Perplexity and Google AI Overviews cite you
fieldnote.app4,571 credits

Site audit

fieldnote.app · SEO, AEO and GEO

Illustrative data
SEO
82
+6
AEO
64
+11
GEO
58
+9
Pages
48
Fixesby impact
  • /pricing · Missing H1High
  • /blog/guide · No FAQ schemaMedium
  • /llms.txt · Not foundMedium
  • /about · Meta description too longLow

See where your whole site stands

Paste your site. The free audit scores it for SEO, answer engines and generative engines, with the fixes.

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