Canonical URL Checker
Paste your page's HTML <head> to check the canonical tag for common mistakes.
A canonical tag tells search engines which URL is the "real" one when the same content is reachable at more than one address — a common situation with pagination parameters, tracking query strings, or a post syndicated to another domain.
Common questions
Why does a relative URL matter if it points to the right page anyway?
A relative URL like "/my-post" resolves against whatever base URL the crawler assumes at the time, which isn't always reliable — a full "https://" link removes that ambiguity entirely and is what search engines expect.
What actually happens with more than one canonical tag?
Search engines are left to guess which one actually applies, and different crawlers can make different guesses — worth catching and removing the duplicate before publishing rather than leaving it to chance.