Crystal Ball checks covered
CANONICAL_MISSING, CANONICAL_CROSS_DOMAIN, duplicate page confusion
What the flag means
A canonical tag is a hint that says, “this is the preferred URL for this page.†Crystal Ball may flag a missing canonical when no preference is visible, or a cross-domain canonical when the page points to a different website as the main version.
This can be harmless on simple sites, but it becomes a problem when duplicate URLs exist. If the wrong canonical is used, search engines may ignore the page you actually want ranked. That is not dark magic. It is just a bad label on the door.
Common causes
Canonical issues often come from CMS defaults, copied templates, HTTP/HTTPS variants, www/non-www versions, trailing slash differences, Shopify product and collection URLs, old domains, staging domains, or SEO plugin settings changed during a rebuild.
How to fix it
- Custom HTML/static: Add one canonical tag in the page
<head>, usually pointing to the final public URL:<link rel="canonical" href="https://example.com/page/">. Google explains canonical URL signals. - WordPress: Most SEO plugins create canonicals automatically. If you need a custom value, Yoast documents canonical URL settings.
- Shopify: Shopify themes usually output canonicals automatically. If you edit theme code, be careful with product, collection, and variant URLs. Shopify’s partner guide explains canonical URL basics.
- Wix: Wix creates default canonicals, but you can change a page’s canonical in Advanced SEO settings. See Wix canonical tags.
- Webflow: Set site-level or page-level canonical tags when needed. See Webflow canonical tags.
Need help?
If the fix gets murky, visit Support and send the details. Bug reports and Crystal Ball questions are free support. Implementation and development work may be paid support, but we will tell you clearly before anything becomes paid. No surprise invoices from the tower.