About this tool
A canonical tag tells search engines which URL is the main version of a page. Paste the page's HTML and its address, and the checker reports whether the canonical is present, absolute, self-referencing and consistent with the rest of the page.
How to use it
- View your page's source and paste the HTML.
- Enter the address of the page exactly as you opened it.
- Read the checks: each one says what is right or what to change.
Questions
Should every page have a canonical tag?
Yes. A self-referencing canonical on each page protects you from duplicates created by tracking parameters, http and https, or www and non-www versions.
Can I use a relative canonical URL?
Google accepts it, but an absolute URL with https:// and your domain avoids mistakes when pages are copied or served from another host.
What if a page is noindex and has a canonical to another URL?
These send mixed signals. Use one or the other: noindex to keep the page out, or a canonical to consolidate it into another page.
Last reviewed 16 October 2026.