← Free tools
Canonical Tag Checker
Bulk-check canonical tags for any list of URLs — flag missing, empty, or non-self canonicals.
Bulk-check canonical tags for any list of URLs — flag missing, empty, or non-self canonicals.
Revuin's canonical tag checker bulk-audits a list of URLs and flags missing, empty, or non-self-referential canonical tags — the kind of small, easy-to-miss issue that can quietly cause duplicate content problems across an entire site.
Paste a list of URLs
The pages you want to bulk-check canonical tags for.
Run the check
Each URL is fetched and its canonical tag inspected.
Review flagged issues
Fix any missing, empty, or incorrect canonical tags found.
An HTML tag (link rel="canonical") that tells search engines which URL is the "master" version when multiple URLs show duplicate or near-duplicate content.
Search engines will make their own guess about which version of a page to index, which can lead to the wrong URL (or a URL variant with tracking parameters) being shown in search results.
It means a page's canonical tag points to a different URL than itself — sometimes intentional, but often a leftover mistake from templating that can accidentally deindex the page.
Yes — completely free, no login required.
Best practice is yes — even a page with no duplicate risk benefits from a self-referential canonical tag, since it removes any ambiguity for search engines.
Yes — cross-domain canonicals are valid and used when the same content is intentionally published in multiple places.
They're the primary tool for telling search engines which version of duplicate or near-duplicate content should be indexed and ranked, consolidating ranking signals onto one URL.