Security & SEO

How does Lemwatch validate canonical URLs?

Lemwatch checks every crawled page for a rel=canonical tag, verifies it resolves to a 200, and flags self-referencing errors or canonical loops.

Updated 2026-07-10

1 min read

seo

canonical

duplicate-content

Quick answer#

On each SEO crawl we look for <link rel="canonical"> on every page, follow it, and confirm the target returns 200. We flag missing canonicals, self-referencing typos, canonical loops, and canonicals that 301/404.

What we detect#

Missing canonical on indexable pages

Canonical pointing to a 404 or 500

Canonical chain (A → B → C)

Canonical to a noindex page

Cross-origin canonical without hreflang

Where to find it in Lemwatch#

Site → SEO → Canonical.

FAQ#

What about paginated pages?#

We treat rel=prev/next as valid canonical alternates.

Hreflang monitoring

SEO monitoring overview

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