A canonical tag tells Google which URL is the definitive version of a page when the same or very similar content is reachable at more than one address. Every page should have one, and it should point at itself unless there is a genuine duplicate elsewhere.
Why it matters
Most sites accidentally serve the same content at multiple URLs: with and without `www`, with and without a trailing slash, or via both `http` and `https`. Without a canonical tag, Google has to guess which version to rank, which can split ranking signals between them.
A canonical tag pointing at the wrong page (a stale value left over from a redesign, for example) can accidentally tell Google to ignore the page you actually want indexed.
How AuditCrow checks this
AuditCrow checks each sampled page for a `<link rel="canonical">` tag in the `<head>`, confirms it resolves to a real, accessible URL, and checks it agrees with the URL the page actually serves at (a related check, C7, looks at canonical agreement across the whole site).
How to fix it
- 1Add `<link rel="canonical" href="https://yourdomain.com/this-exact-page/">` to every page's `<head>`, pointing at the URL you want indexed.
- 2Pick one preferred format for your domain (with or without `www`, trailing slash or not) and set up a permanent redirect from the other versions, rather than relying on the canonical tag alone to paper over it.
- 3Check the canonical tag is not accidentally the same on every page (a common templating bug), which tells Google every page is a duplicate of your homepage.
- 4In WordPress, SEO plugins set this automatically and correctly in almost all cases. A wrong or missing canonical usually points to a custom theme or page builder that has overridden the plugin's output.
Related terms
Related checks
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