What it means
The canonical tag is <link rel="canonical" href="…"> in the <head>. It tells search engines which address to index when the same content is available at several, for example with tracking parameters, filters, or both www and non-www.
We flag pages without a canonical, and canonicals that point to a different domain.
Why it matters
Google treats rel=canonical as a strong hint, not a command. Without it, Google picks a canonical itself; a canonical that points to another site asks Google to index that site’s page instead of yours.
Typical causes of wrong canonicals are a template that prints a fixed address, a site copied from staging with the old domain in it, or a mix of http and https or www and non-www.
How to find it yourself
- View the page source and search for rel="canonical".
- In Search Console, URL Inspection shows the canonical you declared and the one Google selected.
How to fix it
On any website
- Give every indexable page a canonical with its own absolute https address, in the exact form you want indexed.
- Point duplicates (filtered, sorted or tracking versions) to the main page.
- Remove canonicals that point to another domain unless you republish content that lives there.
On Shopify
- Shopify themes output a canonical with {{ canonical_url }} by default. If it’s missing or wrong, check theme.liquid for a hard-coded or duplicate canonical tag.
On WordPress and WooCommerce
- WordPress and SEO plugins add canonicals automatically. Check the plugin’s per-page canonical field for an address left from another site or staging.
How to check the fix
- Run the meta tag checker: it says whether the canonical points to the page itself, another page or another site.
How FixReports finds it
The SEO checker reads the canonical of every page it tests; the meta tag checker classifies it as this page, another page on your site, or another site.