Canonicalization Checker

Free, no signup. Check the canonical Google can see, the HTTP Link header, and whether the chosen target is actually a clean, live URL.

Built by Patrick Stox

Checks run from our server; we fetch the URL you enter and don't keep the results. The URL and its canonical target are fetched to build this report. The full URL is not stored; after a successful check, only its domain may be remembered in this browser. Anonymous run-level outcome counters may be used for aggregate research; URLs, domains, IPs, and identifiers are never included, and no statistic is released below 100 runs.

Feedback
Report a bug

Found something broken in Canonical Checker? Let us know what happened — this goes straight to a private triage queue, not a public list.

What will be sent 
 No tool inputs, uploads, pasted source, complete results, query parameters, or URL fragments are attached automatically. You can edit or remove the selected passage above. Browser and anti-abuse metadata is processed for spam prevention. 
  
 
  
 
 
  
 
 
  
 
Example result
Illustrative example — fixed signals, not a live URL claim
Page checked: https://example.com/product?color=blue
Observed canonical signals
html canonical: https://example.com/product
Google override-risk predictor
LOW — Parameterized page canonicals to a clean URL. Fix: This is usually good when parameters do not change content; ensure internal links and sitemap use the clean URL.
This example assumes the canonical target returns a direct 200. If it redirected or failed, the same engine would add a high-risk finding instead of hiding that evidence.
 
 
 
How to use it
  1. Enter the exact URL variant you want to audit, including parameters when they are part of the question.
  2. Choose Audit canonical. The report shows every HTML and HTTP Link-header canonical observed.
  3. Read the override-risk explanations and fixes, then confirm that the target resolves directly to a live page.
  4. Use Search Console URL Inspection to compare the user-declared and Google-selected canonical for a verified property.
 
 
 
     
     
    
 
What the results mean
The report checks the observable signals involved in CanonicalizationHow search engines pick one canonical URL among duplicates and consolidate signals onto it. and estimates when conflicts may lead Google to select another URL.
  • High marks a direct conflict such as disagreeing canonicals, noindex plus canonical, an unreachable target, or a target that redirects.
  • Medium marks a meaningful consistency risk, including cross-domain targets or hreflang that omits the canonical URL.
  • Low means the observed signals are internally consistent or describe a normal parameter cleanup. It is not a promise that Google agrees.
 
How it works
One bounded server request collects the final URL, response headers, and HTML body. A deterministic parser reads canonical and hreflang links from the head plus canonical Link headers, resolves relative URLs, records duplicates and noindex, and then checks each unique canonical target through the status endpoint. The predictor maps those observed signals to explicit risk reasons and fixes.
 
Features
  • HTML and HTTP Link-header canonical discovery.
  • Relative, missing, multiple, and conflicting canonical checks.
  • Noindex, hreflang, cross-host, protocol, and parameter consistency signals.
  • Bounded canonical-target status and redirect verification.
  • Plain-language likelihood labels without claiming Google's selection.
 
Limitations
The checker reads the server response and does not render JavaScript. It cannot compare page content across duplicate URLs, inspect all internal links or sitemap signals, access Search Console, or observe Google's selected canonical. A low-risk result only describes the evidence fetched in this run.
 
Frequently asked questions
Can this tell me Google’s selected canonical?
No. Google’s selected canonical is only observable through Search Console URL InspectionA Google Search Console feature that reports how Google sees one specific URL on a property you own. By default it shows the last-indexed snapshot; a separate "Test live URL" mode fetches the current version. for a verified property. This tool predicts override risk from observable HTTP and HTML signals.
Does it fetch rendered JavaScript canonicals?
No. It reads the server response. A canonical injected only after JavaScript runs is discouraged and should be verified in URL Inspection.
Should every indexable page have a self-referencing canonical?
A self-referencing canonical is generally useful because it makes the preferred URL explicit and helps keep parameters or alternate URL forms from becoming ambiguous. It is still a hint, not a directive.
Can a canonical point to a redirect?
It can, but it creates a conflicting and inefficient signal path. Point the canonical directly to the final live 200 URL and align internal linksAn internal link is a hyperlink from one page on a website to another page on the same website. Internal links help search engines discover your pages and pass ranking signals (PageRank and anchor-text context) between them., redirects, and sitemap entries with it.
Why might Google ignore a canonical tag?
Google may choose another URL when content, redirects, internal links, sitemapsA sitemap is a file that lists the pages, images, videos, and other files on your site so search engines can discover them. It helps discovery, but submitting a sitemap doesn't guarantee crawling or indexing., hreflangHreflang is an annotation (in HTML, HTTP headers, or XML sitemaps) that tells search engines which language and optional region a page targets, and which alternate versions exist. It only works when every page in the cluster references all the others., protocol or host signals disagree, or when the declared target is unavailable. This checker tests several observable conflicts but cannot see Google’s full index-level evidence.
 
Next stepXML Sitemap Generator — publish a clean sitemap that agrees with your canonical targets.

People also explore
ToolGoogle Index CheckerToolSEO Incident SimulatorToolXML Sitemap ValidatorArticleMagento SEOArticleJoomla SEOArticleCanonicalization
 
 
 
Feature requests for Canonical Checker
 

Upvote what you want most. New ideas can be submitted from the floating Feedback menu;
      requests appear here once approved, and the most-wanted rise to the top.

   
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Common issues & how to fix them
 
     
  •  Warning Canonical is missing Fix: Add one self-referencing absolute canonical URL to the page. 
  •  Error Canonical is relative or invalid Fix: Replace the relative reference with a valid absolute HTTPS URL. 
  •  Error Multiple canonicals conflict Fix: Choose the intended value, align the conflicting signals, and rerun the check. 
  •  Warning Canonical points elsewhere Fix: Point the canonical at the intended preferred URL, or confirm that consolidation is deliberate. 
  •  Error HTML and HTTP canonicals disagree Fix: Choose the intended value, align the conflicting signals, and rerun the check. 
  •  Error Canonical target is not a live 2xx URL Fix: Restore a live 2xx response at the evaluated URL, then rerun the check. 
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