Audit rules

Canonical Invalid

A declared canonical cannot be resolved to an absolute http(s) URL (error), or is a relative URL (warning). In a QuikSEO audit, a failure of this rule has error severity and counts against the score. Below are the exact condition, its exceptions and the sources behind it, followed by the other rules of the same group.

01 — Definition

How This Rule Is Checked

The rule is a pure function of the fetched page: no extra requests, no account settings. The same input always gives the same result.

Rule Severity and Score

Rule id: canonical.invalid
Group: Canonical
Severity of a failure: Error
Counts in the score: Yes, whenever it applies to the page
Required for a score: No

Condition and Exceptions

Condition: A canonical that cannot be resolved to an absolute http(s) URL → fail (error); a relative canonical → fail with severity warning
Exceptions: None declared → not_applicable

Sources and Project Decision

Sources: How to specify a canonical URL with rel="canonical" and other methods (Google Search Central, Q30)
RFC 6596: The Canonical Link Relation (IETF, Q74)
Project decision: Severity error for an unusable canonical and warning for a relative one is a project decision [D]. Protocol-relative values ("//host/path") count as relative; an empty href counts as invalid.

02 — Canonical

Other Rules in This Group

The other checks of the same group, each with its own condition and sources.

Conflicting Canonicalscanonical.conflict
Canonical Differs From Final URLcanonical.differs_from_final_url
Canonical Missingcanonical.missing
Canonical Target Not Indexablecanonical.target_not_indexable