Glossary
Canonical URL
Which version of a duplicated page is the real one.
What it is
A canonical tag names the preferred URL when the same content is reachable at several addresses — with tracking parameters, in a filtered state, or paginated.
Why it costs you money
Stores generate duplicates constantly. Canonicals consolidate ranking signals onto one address instead of splitting them across variants, and they keep the index clean without blocking access.
How to check it yourself
Check what a filtered or parameterised URL declares as its canonical, and confirm the target is the page you want ranking rather than the variant itself.
Where this matters