Broken Canonical Tag

What This Means

The <link rel="canonical"> element is present but its href attribute contains a URL that cannot be parsed as a valid absolute or relative URL — for example, a empty href, a URL with invalid characters, or a mangled template variable that failed to resolve.

Why It Matters for SEO

A canonical tag with a broken or invalid URL provides zero canonicalization benefit. Search engines discard malformed canonical hints and fall back to their own canonical selection logic. Worse, the broken tag may be a symptom of a template rendering failure that is producing other malformed output on the page.

What the Platform Checks

The platform parses the href attribute of each canonical element. Fires when the value cannot be parsed as a valid URL (empty string, contains template variables like {pageUrl}, contains invalid characters, or is completely missing).

How to Fix It

• Investigate the source of the malformed URL — check CMS templates, plugin settings, or custom code that generates canonical tags.
• Look for unresolved template variables: e.g., href="{canonical_url}" where the variable was never defined.
• Ensure the canonical href is always a fully-qualified absolute URL (https://yourdomain.com/page/).
• After fixing, re-crawl and verify the canonical resolves to a valid 200 URL.