Why it matters for your business
The same page can often be reached at several addresses: with and without “www”, with tracking codes added, or through different menu paths. To a search engine, these can look like separate, duplicate pages. A canonical tag points them all to one preferred address, so search engines know which one to show.
Google treats the canonical tag as a strong hint rather than a strict rule, and it may choose a different main version if other signals disagree.
Example
These addresses all show the same page:
https://yourdomain.com/services/drain-cleaninghttps://www.yourdomain.com/services/drain-cleaninghttps://yourdomain.com/services/drain-cleaning?utm_source=facebook
Each version includes this tag in its code, pointing to the preferred address:
<link rel="canonical" href="https://yourdomain.com/services/drain-cleaning">How to check or improve it
- Give every page a canonical tag pointing to itself, using your preferred address.
- Redirect alternate versions, such as “www” or “http”, to the preferred one.
- Use the same preferred addresses in your sitemap and internal links.
- In Google Search Console, check the Pages report for “Duplicate” warnings.