non-self canonicals
Pages pointing their canonical tag to a different URL may lose ranking signals
What it is
crawler.sh flags a page as having a non-self canonical when its <link rel="canonical"> tag points to a different URL than the page itself. This is check #13 in the SEO analysis.
Why it matters for SEO
The canonical tag tells search engines which URL is the “preferred” version of a page:
- Intentional consolidation - Non-self canonicals are correct when multiple URLs serve the same content (e.g., with/without query parameters, HTTP/HTTPS variants, www/non-www). The canonical consolidates ranking signals to one URL.
- Accidental misconfiguration - If a page incorrectly points its canonical to a different page, search engines will ignore the current page in favor of the canonical target, effectively de-indexing it.
- Cross-domain canonicals - Pointing canonicals to a different domain is rarely correct and can cause the page to be excluded from your site’s search results entirely.
Caution: An incorrect canonical tag is one of the most common and damaging SEO mistakes. It can silently remove pages from search results without any visible error.
Why it matters for AEO
AI answer engines use canonical tags to determine the authoritative version of content. If a page has a non-self canonical, the AI will prefer the canonical target as the source. Misconfigured canonicals can cause AI systems to attribute your content to the wrong URL or skip it entirely.
How to fix it
Review each non-self canonical and verify it’s intentional:
Correct uses of non-self canonicals:
- URL variants (query parameters, tracking codes) pointing to the clean URL
- Mobile/AMP pages pointing to the desktop version
- Syndicated content pointing to the original source
Common misconfigurations:
- All pages pointing to the homepage (often a CMS bug)
- Pagination pages canonicalizing to page 1 when they have unique content
- Relative canonical URLs that resolve incorrectly
<!-- Self-referencing canonical (most pages should have this) --><link rel="canonical" href="https://example.com/current-page">
<!-- Non-self canonical (use only when intentional) --><link rel="canonical" href="https://example.com/preferred-page">What crawler.sh reports
In the CLI, non-self canonicals appear under the “Non-self canonicals” section of crawler seo output. Each affected URL is listed alongside its canonical target. In the desktop app, they appear in the SEO Issues card.
