Canonical URL Checker
Find the canonical URL a page declares, in its HTML or HTTP headers, and check it's usable: in the right place, not conflicting, and pointing to a page that works.
What a Canonical URL Is
The same page is often reachable at several URLs: with and without www, over http and https, with tracking parameters such as ?utm_source=, or with a trailing slash. A canonical tells search engines which URL you want them to index and show. It's declared in the page's <head>:
<link rel="canonical" href="https://www.example.com/product">
For files that aren't HTML, such as PDFs, it goes in an HTTP header instead: Link: <https://www.example.com/guide.pdf>; rel="canonical". Google explains the other ways to signal a preference, including redirects and sitemaps, in How to specify a canonical URL.
What the Checker Looks At
- Every declaration: rel=canonical links in the HTML and in Link headers, and whether each is inside <head>. Google ignores canonicals in the body.
- Conflicts: different canonicals in the same page, or HTML and header disagreeing. Google may then ignore all of them.
- The target: whether the canonical URL itself returns 200, redirects or fails.
- How it differs from the page URL: http and https, www, another domain, trailing slash or query string.
- Mixed signals: a noindex together with a canonical pointing elsewhere, and canonicals on error or redirect responses.
It reads the HTML the server sends. Canonicals added later by JavaScript aren't seen; Google can render JavaScript, but recommends not changing the canonical that way.
Common Mistakes
- A theme or plugin adds a second canonical, often with a different URL. Check the page source and keep one.
- Every page points to the homepage, usually from a template bug. Google then treats the pages as duplicates of it and may ignore the tags.
- The canonical points to a redirect or a 404. Point it at the final URL that returns 200.
- An element that belongs in <body>, such as an <img>, <iframe> or stray text, appears in <head> before the canonical. Browsers then end <head> early and the canonical lands in the body.
- Canonicals copied from staging, so the live site points at a test domain. Using absolute URLs generated from your production domain avoids this.
How the Check Is Made
The URL is sent to Orbit2x's server, which requests the page, reads up to 2 MB of its HTML and its headers, and, if the canonical points elsewhere, requests that URL once to see whether it works. Nothing is stored. Private and local network addresses are refused. See the privacy policy for general data practices.
Frequently Asked Questions
Is there a penalty for duplicate content?
Not for ordinary duplicates such as tracking parameters, print versions or www and non-www copies. Google picks one URL to show and folds the others into it. A canonical helps you choose which one. Copying content from other sites to manipulate rankings is a different matter, covered by Google's spam policies.
Does every page need a canonical tag?
It's optional. If you don't declare one, Google chooses a canonical itself, which works for most pages without duplicates. A self-referencing canonical is a cheap way to make your preference explicit, especially on pages that get linked with parameters.
Why does Google show a different canonical from mine?
A canonical is a strong hint, not a rule. Google also weighs redirects, sitemaps, internal links and whether the pages really are duplicates. If your signals disagree, for example the canonical says one URL and your internal links use another, Google may pick its own. The URL Inspection tool in Search Console shows both the user-declared and the Google-selected canonical.
Should paginated pages point their canonical to page 1?
No. Each page in a series has different content, so give each one a self-referencing canonical. Pointing them all at page 1 can stop the items on later pages from being found.
Can a canonical point to another website?
Yes. Cross-domain canonicals are supported, for example when the same article is published on two sites you control. If a partner republishes your content, Google suggests they block indexing of their copy with noindex, because a cross-domain canonical may not always be followed.