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.
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.
Example result
Illustrative example — fixed signals, not a live URL claim
Page checked: https://example.com/product?color=blue
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
- Enter the exact URL variant you want to audit, including parameters when they are part of the question.
- Choose Audit canonical. The report shows every HTML and HTTP Link-header canonical observed.
- Read the override-risk explanations and fixes, then confirm that the target resolves directly to a live page.
- Use Search Console URL Inspection to compare the user-declared and Google-selected canonical for a verified property.
+ saves the current site or page. Use ☆ beside any saved site, page, or list to favorite it. Recent check history appears below.
Create a named list
Target filled from your local choices.
Site passport Local context for this saved site
Local data
Saved targets, named lists, and recent check summaries remain only in this browser.
Observed canonical signals
Google override-risk predictor
This is a deterministic signal check, not a claim about Google’s indexed canonical.
Why these verdicts and how to verify them
Portable baseline
Download this result as JSON, then import it after a later run of the exact same URL. The baseline stays in your files and is not uploaded.
Rate this tool
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 Inspection 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 links, redirects, and sitemap entries with it.
Why might Google ignore a canonical tag?
Google may choose another URL when content, redirects, internal links, sitemaps, hreflang, 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.
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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Acerca de la herramienta
Audita las señales de canonicalización en HTML y HTTP, comprueba el destino canonical y obtén una explicación basada en evidencia de las señales que pueden hacer que Google seleccione otra URL canonical.
Funciones
- Descubrimiento de canonicals en HTML y en los encabezados Link de HTTP. Comprobaciones de canonicals relativas, ausentes, múltiples y en conflicto. Señales de noindex, hreflang, host cruzado, protocolo y coherencia de parámetros. Estado acotado del destino canonical y verificación de redirecciones. Etiquetas de probabilidad en lenguaje claro sin afirmar la selección de Google.
Cómo funciona
Cómo funciona: una solicitud acotada al servidor sigue la URL, devuelve las cabeceras de respuesta y el cuerpo HTML. Un analizador determinista extrae los enlaces canonical y hreflang de la cabecera y las cabeceras Enlace de canonical, resuelve las URL relativas, registra duplicados y noindex y después comprueba cada destino de canonical único mediante el punto final de estado. El predictor traduce esas señales observadas en motivos de riesgo y correcciones explícitos.
Limitaciones
- Limitaciones: el comprobador lee la respuesta del servidor y no renderiza JavaScript. No puede comparar el contenido de páginas con URL duplicadas, inspeccionar todos los enlaces internos ni las señales del sitemap, acceder a Search Console u observar la canonical seleccionada por Google. Un resultado de bajo riesgo solo describe la evidencia obtenida en esta ejecución.
Preguntas frecuentes
¿Por qué podría Google ignorar una etiqueta canonical?
No. Lee la respuesta del servidor. Una canonical inyectada solo después de que se ejecute JavaScript no es recomendable y debe verificarse en Inspección de URL.
¿Puede esto decirme cuál canonical seleccionó Google?
Google puede elegir otra URL cuando el contenido, las redirecciones, los enlaces internos, los sitemaps, hreflang, el protocolo o las señales del host no coinciden, o cuando el destino declarado no está disponible. Este comprobador prueba varios conflictos observables, pero no puede ver toda la evidencia del índice de Google.
¿Debe toda página indexable tener una canonical autorreferente?
No. La canonical seleccionada por Google solo puede observarse mediante Inspección de URL de Search Console para una propiedad verificada. Esta herramienta predice el riesgo de sobrescritura a partir de señales HTTP y HTML observables.
¿Puede una canonical apuntar a una redirección?
Una canonical autorreferente suele ser útil porque hace explícita la URL preferida y evita ambigüedades entre parámetros o formas alternativas. Sigue siendo una indicación, no una directiva.
¿Puede una canonical apuntar a una redirección u otra URL?
Puede, pero crea una ruta de señales conflictiva e ineficiente. Apunta la canonical directamente a la URL final activa con respuesta 200 y alinea con ella los enlaces internos, las redirecciones y las entradas del sitemap.