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Missing canonical tag

canonicals.missing
Priority
Medium
Severity
Warning

What we look for

These pages give no canonical tag (a line in <head>, or a server header, that names a page's preferred address).

Why it matters

Without one, search engines guess which address to show when a page can be reached at several, for example with and without tracking tags, and may pick one you did not want.

How to fix

Add a canonical tag to the <head> of each page that names the page's own full address, through the page template or an SEO plugin.

Seen in a real crawl

From a crawl of Millbrook Hardware (the broken fixture), a test site from Raptor’s fixture suite.

Medium

2 pages do not name their preferred address

  • /soft-404
  • /title-outside-head
Paths on http://127.0.0.1:8001raptor 0.3.0, 17 Oct 2026

Open this finding in that crawl’s report

It also fired on Kestrel Bay Digital.

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.missing
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.missing"
The HTML report
This link opens the finding in the report, and each finding shows its id.
crawl.html#finding=canonicals.missing
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.missing"
}