Canonical URL Checker
Paste a page's HTML and its URL to see which address it declares as canonical — and whether that's the page itself, another URL, missing, relative, misplaced or in conflict with other signals.
How to use the Canonical URL Checker
Paste the HTML
Page source is best, because canonical tags belong in the server-rendered head.
Add the page URL
Needed to decide whether the canonical is self-referencing and to resolve relative values.
Read the status
Confirm it matches your intent — usually self-referencing for primary pages.
Fix conflicts
Keep exactly one canonical per page, absolute, in the head.
What it checks
- Relationship
- Self-referencing, pointing to another URL, or missing — comparing ignoring trailing slash and letter case.
- Multiple declarations
- More than one canonical, and whether they agree.
- Placement
- Canonical links inside the body, which search engines may ignore.
- Format
- Relative URLs, empty hrefs and http:// canonicals on https pages.
- Consistency
- og:url that differs from the canonical, and canonicals combined with noindex.
Interpreting the results
The status line summarises the verdict; the declarations table shows each canonical as written, as resolved to a full URL, and where it sits. A canonical is a hint: search engines may choose a different canonical if other signals — redirects, internal links, sitemaps — disagree.
“Points elsewhere” isn't automatically wrong. It's correct for filtered, sorted or tracking-parameter versions of a page. It's a problem when the page should rank on its own.
Detected marks facts read directly from what you provided. Guidance marks general recommendations based on those facts — rules of thumb, not guarantees or search engine requirements.
Practical guidance
Canonical mistakes are usually template mistakes: a CMS that outputs the homepage as canonical on every page, a pagination plugin pointing page 1 at ?page=1, or a staging domain left in the tag after launch. Check one page from each template type and you'll catch most of them.
Canonicals matter directly for link building. If a page canonicalises to another URL, links pointing at it may be consolidated to that other URL. That's why confirming a self-referencing canonical is part of our target-page checklist, and why we check host articles before a niche edit. For a live check including the HTTP Link header, use the SEO Page Analyzer; for international sites, pair canonicals with correct annotations using the Hreflang Generator & Validator.
Limitations
- HTTP Link headers aren't part of HTML, so they can't be read from pasted source — the SEO Page Analyzer checks them on a live fetch.
- It checks what's declared, not which canonical a search engine has actually chosen; only Search Console shows that.
- Canonicals added by JavaScript are only seen if you paste rendered HTML.
Frequently asked questions
Should every page have a canonical tag?
A self-referencing canonical is a sensible default for indexable pages. It removes ambiguity between URL variants.
Is a canonical the same as a redirect?
No. A redirect sends visitors elsewhere; a canonical leaves the page accessible and suggests which URL search engines should treat as primary.
Can I use a relative canonical URL?
It's allowed, but absolute URLs are less error-prone.
Is my HTML uploaded?
No. It's analysed in your browser.
Related tools
- SEO Page Analyzer
Fetch a live URL and review status, tags, headings, links, images and schema in one report. - Hreflang Generator & Validator
Generate hreflang tags for HTML, sitemaps or headers — and validate existing ones. - Redirect Rule Generator
Create 301/302 redirect rules for Apache .htaccess or Nginx from a list of URLs. - Meta Tag Analyzer
List every meta and link tag in a page's head, with length checks and advice.
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