How to use this tool
Check whether a page declares a self-referencing HTTPS canonical — and catch www vs non-www, staging hosts, and path mismatches that split Google rankings.
Also try the full free SEO checker or browse all free SEO tools.
About this canonical url checker
Why it matters
Canonical tags tell Google which URL is the preferred version when www, apex, trailing slashes, or UTM parameters create duplicates. A missing or wrong canonical splits impressions — software and SaaS sites hit this constantly after staging launches and CDN cutovers.
How it works
- Paste any public URL (we follow redirects to the final host).
- We read <link rel="canonical"> from the initial HTML.
- We compare scheme, host, and path against the fetched URL and flag mismatches.
- Use the fix hint, then 301 the non-preferred host and re-check.
Best practices
- Prefer one public host (usually www or apex) and 301 the other.
- Use absolute HTTPS self-referencing canonicals on indexable pages.
- Never leave staging, localhost, or preview hosts in production canonicals.
- Strip tracking query params from the canonical; keep clean paths.
- Pair with Search Console coverage and a full SEO check after large URL migrations.
Related free tools
Canonical URL Checker FAQs
What is a canonical URL checker?
A canonical URL checker fetches a page and inspects the <link rel="canonical"> tag: whether it exists, uses HTTPS, matches the preferred host, and self-references the page you meant to index. DebuggedSoftware’s free checker does that for any public URL.
Should every page have a self-referencing canonical?
Most indexable pages should. Self-referencing HTTPS canonicals make the preferred URL explicit when parameters, shares, or slight path variants appear. Pagination and true duplicates may point elsewhere on purpose.
What is a www vs non-www canonical mismatch?
It means the HTML canonical uses www.example.com while the fetched page (or vice versa) uses example.com. Pick one preferred host, 301 the other, and align every canonical with that host.
Can a wrong canonical hurt SEO?
Yes. Pointing money pages at staging, the wrong path, or the non-preferred host can dilute rankings or keep the wrong URL indexed. Fix redirects and canonicals together.
Is this canonical URL checker free?
Yes. It shares DebuggedSoftware’s three free SEO checks per day with our other tools. Need www/apex redirects and template fixes across a site? We implement them in Django, Laravel, WordPress, Next.js, and more.
Does this follow redirects?
Yes. We fetch the URL, follow redirects to the final location, then compare that final URL to the canonical tag in the HTML. Chain length and hop details are covered in a dedicated redirect checker later.