Google supports relative canonical values but recommends absolute URLs to reduce deployment and base-URL mistakes.
SEO & search
Compare a page URL with its declared canonical.
See whether the URLs self-reference, point across pages, or change hosts. Review every important component and copy clean markup—without a live crawl or made-up canonical score.
- Runs in your browser
- Absolute and relative hrefs
- No live crawl or fake score
Compare the declared URLs
Check the canonical relationship.
The absolute HTTP(S) URL where the canonical element will be placed.
Paste the href value—not the whole link element. Relative values can be checked, but Google recommends an absolute URL.
Compared locally
The browser parses these strings as URLs. It does not request either page, resolve DNS, inspect HTML, or send the values anywhere.
Runs entirely in your browser. No URLs are requested, sent, or stored.
Review before publishing
Canonical finding
The canonical points to another URL on the same hostname. Confirm that the target is duplicate content or a content superset.
Place this element inside the HTML <head>.
Parsed URLs
- Page
https://example.com/products/blue-widget?ref=email- Canonical
https://example.com/products/blue-widget
URL differences
- Canonical formatMatch
The canonical value is an absolute HTTP(S) URL.
- ProtocolMatch
Both URLs use https:.
- HostnameMatch
Both URLs use example.com.
- PortMatch
Neither URL uses a non-default port.
- PathMatch
Both URLs use /products/blue-widget.
- Query stringReview
The page has a query string and the canonical omits it. That is common for duplicate variants, but the tool cannot verify content equivalence.
- FragmentMatch
Neither URL contains a fragment.
What this checker cannot verify
- Whether either URL loads, redirects, is crawlable, or is indexable.
- Whether the pages contain duplicate or superseding content.
- Whether this element appears once inside a valid HTML head.
- Which URL Google selected as canonical.
A declared canonical is a preference signal—not a guarantee.
Use it with context
A difference is a prompt to verify—not proof of a mistake.
Canonicals can intentionally point to another page or hostname when the target represents duplicate or more complete content. This checker compares URL syntax; it cannot inspect the content or know which URL a search engine selected.
Align canonical elements with redirects, sitemaps, internal links, and hreflang choices where those signals apply.
Canonical means preferred—not guaranteed.
Google treats a declared canonical as a signal and may select a different URL. Use Search Console and rendered-source checks for live-site verification.
Primary sources
Guidance you can verify.
Reviewed August 22, 2026. Canonical behavior and search guidance can change, so the checker links its wording to current documentation and web standards.