Invalid Attribute in Canonical Tag

What This Means

The <link rel="canonical"> element contains an attribute that is invalid, malformed, or incorrectly formatted — for example, the rel attribute value is misspelled, the element is not a self-closing void element, or additional unknown attributes are interfering with parsing.

Why It Matters for SEO

An invalid canonical attribute means the element may not be recognized as a canonical link by search engine parsers. The canonicalization benefit is lost if the tag is not correctly formed.

What the Platform Checks

The platform validates the canonical link element's attribute structure — verifying the rel value is exactly "canonical", the href is present and well-formed, and no attributes interfere with parsing. Fires when the element has structural issues.

How to Fix It

• Ensure the canonical tag exactly follows the specification: <link rel="canonical" href="https://yourdomain.com/page/">
• Check for typos in the rel attribute ("cannonical", "Canonical", "canonical link").
• Remove any extra attributes from the element that are not part of the canonical specification.
• Validate the complete tag markup.