Canonical URL Checker
NewPaste HTML and your page URL to check canonical tag presence, validity, self-referencing status, and common SEO mistakes like duplicate or relative canonicals.
Frequently Asked Questions
Why does it flag a relative canonical URL as a warning?
Google explicitly recommends using an absolute, fully-qualified canonical URL (including the https:// scheme and host) rather than a relative path, since a relative URL can be ambiguous depending on how the crawler resolves the base URL.
What does "self-referencing canonical" mean, and is it a problem?
It means the canonical tag points to the exact same URL as the page it's on — this is completely normal and is actually the recommended default for most pages that aren't duplicates of another URL.
Why does having multiple canonical tags matter?
When a page has more than one <link rel="canonical"> tag, search engines may ignore all of them or choose one unpredictably, effectively leaving the page without reliable canonicalization — the tool flags this as an error.
Does this check whether the canonical URL actually exists or returns a 200 status?
No — this tool only statically analyzes the HTML and URL structure you paste; it doesn't make any network requests, so it can't confirm the target URL is live or returns the expected status code.
Can I paste just the <head> section instead of a full HTML document?
Yes — the tool searches for a <link rel="canonical"> tag anywhere in the pasted text using a regular expression, so a full document, a <head> fragment, or even just the single tag all work.