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Canonical Tag Checker

Fetch a site's home page and see the canonical URL, og:url, and robots meta tag it declares — then check whether the canonical points back to the fetched URL.

How to use this tool

  1. 1

    Enter a domain or URL (for example example.com or https://example.com) in the input field.

  2. 2

    Submit to fetch the page server-side over HTTPS, falling back to HTTP if needed.

  3. 3

    Read the results: the requested URL, the declared canonical, og:url, and the robots meta value.

  4. 4

    Check the match indicator to confirm whether the canonical equals the fetched URL or differs.

What is a canonical tag and what does this checker actually inspect?

A canonical tag is a <link rel='canonical' href='...'> element in a page's <head> that tells search engines which URL is the preferred version when the same or similar content is reachable from several addresses (http vs https, www vs non-www, trailing slashes, tracking parameters, print views). Google treats it as a strong hint, not a directive, and consolidates ranking signals onto the chosen URL. A canonical that points to the wrong page or domain is a common cause of pages dropping out of the index. This checker performs a server-side fetch with a desktop browser User-Agent, follows up to five redirects while blocking private and internal hosts, then parses the returned static HTML with Cheerio. It reads the first <link rel='canonical'> href, the og:url meta property, and the robots meta tag. One important limitation: it normalizes your input to the bare host and fetches only the site root, so the path you type is ignored — it always reports the home page's tags. It also does not execute JavaScript, does not read canonicals sent via the HTTP Link header, and the match check is an exact string comparison against the final fetched URL.

Common use cases

  • Confirming your home page canonicalizes to your preferred https, www-or-not version after a migration.

  • Diagnosing why a freshly launched site stopped appearing in Google by checking its root canonical and robots value.

  • Spot-checking whether a CMS or theme injected a hard-coded canonical pointing at a staging or template domain.

  • Verifying that og:url and the canonical agree, so social shares and search both reference the same address.

  • Auditing a competitor's home page to see how they handle canonicalization and indexing directives.

  • Quickly reading a site's robots meta tag to spot an accidental noindex on the home page.

Frequently asked questions

Does this check the exact deep URL I paste?▼
No. The tool strips your input down to the host name and fetches only the site root, so a path like /blog/post is ignored. It always reports the home page's canonical, og:url, and robots tags. To inspect a deep page you would need a tool that fetches the full path.
What does the 'matches' indicator mean?▼
It is an exact string comparison between the declared canonical href and the final URL after redirects. A relative canonical, a trailing-slash difference, or http vs https mismatch will show as 'differs' even when search engines would treat them as equivalent.
Why does it say no canonical when my page has one?▼
The fetch reads static HTML only and does not run JavaScript. If your canonical is injected client-side by a framework, or sent only through the HTTP Link header rather than a <link> tag, this tool will not see it.
Is my data uploaded anywhere?▼
The page you submit is fetched by this site's server, not your browser, and the result is returned to you. The only thing sent is the URL you enter; no page content is stored or shared beyond producing your result.
What happens in SEO terms if the canonical points elsewhere?▼
Search engines may consolidate ranking signals to the target URL and index that page instead of the one you requested. If a page canonicalizes to the wrong domain by mistake, it can effectively disappear from search for its own address.
Can I check internal or localhost URLs?▼
No. For security the fetcher blocks private, loopback, link-local, and cloud-metadata addresses, and rejects single-label hosts. It only works against public domains with a real TLD.
Does a missing robots value mean my page is blocked?▼
The opposite. When no robots meta tag is present the result notes that the default is index, follow — meaning the page is eligible to be indexed and its links followed unless blocked elsewhere, such as in robots.txt or an HTTP header.

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