canonical.invalid

What to change

A finding of this rule on a page carries the exact edits for that page: the markup it quotes, and what to write instead.

When it runs

Runs on every SEO audit: of a page, a crawl, a build directory or HTML. An error is a problem that keeps a page out of search or out of answers, or breaks how it shows there. Each finding takes 15 points off the page's score.

The severity here is the rule's usual one: a finding can be raised or lowered when the page gives a reason.

Run it, or skip it

Check a page for this rule alone, after a fix for instance:

npx @rivi-software/agentic-seo-check audit https://example.com --rule canonical.invalid

Or from an assistant, with the MCP tool seo_audit_page:

{
  "url": "https://example.com",
  "rules": [
    "canonical.invalid"
  ]
}

To leave it out of an audit, pass --disable canonical.invalid on the command, or disableRules: ["canonical.invalid"] to a tool.

• Warningcanonical.missingNo <link rel="canonical"> is present.
• Errorcanonical.header-conflictThe HTTP Link header names a different canonical URL than the page's <link rel="canonical">, or names more than one.
• Errorcanonical.multipleMore than one canonical link is present. When they disagree, search engines ignore all of them.
• Warningcanonical.relativeThe canonical href is a relative URL.
• Warningcanonical.protocol-mismatchThe page is served over https but the canonical points to http.
• Infocanonical.other-pageThe canonical points to a different URL, so search engines will treat this page as a duplicate of that URL.
• Warningcanonical.paginated-to-firstPage 2 or later of a paginated series (?page=2, /page/2/) names the first page as its canonical, so search engines may drop it and miss the items only it links to.