SEO Tools
Canonical tag checker.
Paste a page's HTML and see whether its rel=canonical tag is present, single, absolute, free of fragments and inside the head. Add the page URL to test whether it points at itself.
Input
Result
Paste the page HTML, then press Check.
How the canonical tag checker works
The tool reads the pasted source as text, finds every <link> whose rel contains canonical, and runs the checks below. It ignores anything inside HTML comments, scripts and styles. Nothing is fetched, so it cannot tell you what a live URL redirects to or what Google chose as canonical.
Worked example
Click Load example. The sample declares /widgets/blue/ (relative) and https://example.com/widgets/blue/?ref=nav (a different absolute URL). Result: the two canonicals conflict (fix), the first is not absolute (review), and the og:url differs from it (note). Keep one canonical, absolute, and equal to the URL you want in search.
What is checked
- Present, and only one. Different canonicals on one page are a fix; the same one repeated is a review.
- Inside
<head>. Google only accepts it there. - Absolute URL. Google supports relative paths but recommends absolute ones.
- No
#fragment. Google says not to use a fragment as canonical. - Not paired with
noindexon the same page, and equal toog:urlwhen both exist. - With the optional page URL: whether the canonical points at the page itself.
A canonical is a hint. Google may choose a different URL, and the HTTP Link header form cannot be seen in pasted HTML.
Sources
Sources reviewed October 2026.
Canonical Tag Checker FAQ
How many canonical tags should a page have?
One. Google says not to specify different canonical URLs for the same page, and conflicting canonicals may be ignored. This tool reports different URLs as a fix and an exact repeat as a review.
Should the canonical be absolute or relative?
Google supports both but recommends absolute paths, because relative ones can cause problems in the long run. The tool flags relative values for review.
Can I use noindex and a canonical together?
Google does not recommend noindex as a way to choose a canonical, because noindex removes the page from Search entirely. Use rel=canonical for duplicates. The tool raises a review when both are present.
Does it fetch my URL?
No. Paste the HTML source (View Source, or curl output). Pasted markup is parsed as text and never loaded.
Does a canonical tag guarantee Google uses that URL?
No. It is a strong hint, not a directive. Redirects, sitemaps and internal links are other signals.