What is a topic cluster?
Definition
A topic cluster is a group of pages covering one subject: a pillar page on the broad topic, supporting pages on its parts, and internal links connecting them.
A cluster makes a site's expertise easy to see. Instead of scattered posts that each chase a different phrase, the pages are planned together: the pillar covers the whole subject at a useful depth, each supporting page answers one specific question in detail, and every page links to the pillar and to the related pages beside it.
That structure helps in three practical ways. Search engines find every page through the links. The grouping signals which pages belong to which subject. And a reader who lands anywhere in the cluster can move straight to the next question they have. A starter cluster is usually one pillar plus four to eight supporting pages, sized to the market and the budget. That is also why a cluster is planned before any of it is written.
Why does it matter to your business?
One post rarely ranks for a competitive topic on its own. A cluster gives a small site a way to cover a subject completely, and to show that it has.
Related terms
Last reviewed September 11, 2026 by Joseph Nicholas Abear.
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