Dead-end canonical: what it means and how to fix it

What we look for

Each page's canonical tag (the line in <head> that names the preferred address) points to a page that returns an error (a 4xx or 5xx status code) or is marked noindex (told search engines not to list it).

Why it matters

Search engines may ignore the tag or leave both pages out of results, because the version you asked them to show cannot be shown.

How to fix

Point each canonical tag at a live page that loads normally and is not marked noindex. Usually that is the page's own address.

Seen in a real crawl

From a crawl of Fernhollow Outdoor, a test site built for this site’s demo.

Fix now

1 page names a preferred version that search engines cannot use

/waterproofs/storm-shell/Canonical /products/storm-shell - Target status 404

Paths on http://127.0.0.1:8006raptor 0.3.0, 17 Oct 2026

Open this finding in that crawl’s report

Where you’ll see it

The id is stable, and every surface uses it, so it’s the thing to search for or hand to an agent.

Terminal: When it is one of the five findings under Fix first, raptor crawl prints the id under it.
Check: canonicals.non_indexable_target
crawl.json and the CSV: The crawl JSON names the finding by this id, and so do the CSV and raptor_query.
"check_id": "canonicals.non_indexable_target"
The HTML report: This link opens the finding in the report, and each finding shows its id.
crawl.html#finding=canonicals.non_indexable_target
MCP: raptor_findings with this check_id returns the finding in full, with a fix brief ready to paste into a task. If it didn’t fire, it says why.
raptor_findings { "job_id": "...", "check_id": "canonicals.non_indexable_target" }