Canonical tag checker
Checks a page's rel="canonical" tag: presence, count, whether it is self-referencing, and whether the URL it names actually resolves.
1 · Input
What is checked
Whether a page has a rel="canonical" link tag, whether more than one is present (invalid - a page should declare at most one), whether the URL it names is absolute, whether it points back to the same page (self-referencing) or to a different URL entirely, and whether that target URL actually resolves rather than 404ing.
Self-referencing is not always wrong
A canonical pointing somewhere other than the page it is found on is completely normal when that page is a deliberate duplicate - a print view, a tracking-parameter variant, or paginated content pointing at a primary page. This tool reports the fact; whether it is the intended outcome depends on the site.
Rate this tool
Was this tool useful? Your feedback helps us improve it.