TECHNICAL SEO
Canonical Consistency Checker
Search engines decide which of several similar URLs to index from many hints: the canonical tag, the Link header, redirects, hreflang and internal links. When those hints disagree, Google picks for you. This check reads them together and follows the canonical to see where it really leads.
- Checks the live page
- Public addresses only
- Free, no sign-up
- CheckCanonical present, single and absolute
- CheckHTML canonical against the Link header canonical
- CheckCanonicals pointing to redirects, errors or noindex pages
- CheckCanonical chains (the target names yet another URL)
Free
no sign-up
Live
fetched when you run the check
6 checks
what the tool looks at
30 a minute
checks per visitor, to keep it free
Loading the tool…
HOW IT WORKS
How to use the Canonical Consistency Checker
One public page URL.
Enter the URL of the page you want indexed (or a variant of it).
Read the checks, then the table of signals underneath.
Make every signal name the same final URL.
WHAT IT CHECKS
What it looks at, and how to read it.
Checks on every canonical signal, a check of the target page when the canonical points elsewhere, and a table of the signals found.
What it checks
- Canonical present, single and absolute
- HTML canonical against the Link header canonical
- Canonicals pointing to redirects, errors or noindex pages
- Canonical chains (the target names yet another URL)
- og:url and hreflang naming a different URL
- Tracking parameters and http:// in canonicals
How to read the results
- Conflicting canonicals cancel each other out: Google ignores them all.
- A canonical to a redirect or a noindex page wastes the signal or loses both pages.
- A self-referencing canonical is the safe default for pages that should rank themselves.
The concepts behind it, in the SEO glossary: Canonical tag, Duplicate content.
GOOD TO KNOW
Common mistakes, an example and the limits.
Common mistakes
- Every page’s canonical pointing to the homepage after a theme bug.
- An SEO plugin and the server both adding canonicals that differ.
- Canonicals on paginated pages pointing to page one.
A worked example
A shop’s filtered URLs carry a canonical to /phones, which redirects to /phones/. Pointing the canonical straight at /phones/ removes the redirect from every signal.
Limitations
- Checks the HTML the server sends. Content a page adds with JavaScript after loading is not seen.
- Some sites block or challenge automated requests; then the result shows what a crawler without a browser would get.
- A canonical is a hint. Google may still choose another URL, for example when the pages’ content differs a lot.
FAQ
Questions about the Canonical Consistency Checker
Straight answers about what it does and where its limits are.
What is the difference between a canonical and a redirect?
A redirect sends visitors and crawlers to another URL. A canonical keeps the page reachable and asks search engines to index another URL instead.
Can a canonical point to another domain?
Yes, for syndicated content. Google treats cross-domain canonicals as a hint, like any other.
Find canonical problems on every page of your site.
Free tools check one thing at a time. The NdovuSEOLabs platform connects your own Search Console, analytics and server logs, and keeps checking every page.