Canonical tag checker
Paste a URL. We read the canonical tag, resolve it, and tell you which URL this page is asking Google to index - which is not always the one you expect.
Free, no account, no card. One URL at a time.
What this checks
- What it points at
- Resolved to an absolute URL, so a relative canonical is shown as what it actually means.
- Self-referencing or not
- Correct for a duplicate; a mistake if this page is the original.
- More than one
- Two canonical tags and Google ignores both.
- http from https
- A canonical asking Google to index the insecure copy.
- The HTTP header too
- A canonical can be set in a Link header as well, and two sources can disagree.
Why it matters
A canonical is a hint, not an instruction, and Google follows it most of the time. That is enough to matter: a page canonicalised to another URL is telling search engines not to index it, and the traffic goes to whatever it points at.
The expensive version is a template. A canonical hard-coded to the homepage, or to the non-www host, or left pointing at a staging domain, is applied to every page using that template - and every one of them disappears together.
Filtered and sorted URLs are the everyday case: ?colour=blue should usually canonicalise to the plain product listing. This tells you what a given URL is actually claiming.
Questions
- Does every page need a canonical?
- No, and a self-referencing one on every page is a reasonable default. It costs nothing and it settles the question when the same page is reachable at more than one URL.
- Canonical or noindex?
- Different jobs. A canonical consolidates duplicates into one URL; noindex removes a page from search. Using both on one page sends contradictory signals, which the full audit flags.
- Is a relative canonical wrong?
- Legal, and risky. It resolves against the current URL, so the same template on a different host silently points at that host - a common way for a migration to canonicalise a site onto the wrong domain.
One URL is a spot check
The full audit covers missing canonicals, canonical loops, canonicals to redirects or noindexed pages, and header conflicts - across every page it crawls, with a score and a ranked list of what to fix first.