What is Topic Cluster?

Updated June 2026
Definition

A topic cluster is a group of interlinked pages that cover a subject comprehensively, usually a central pillar page plus many supporting pages that link to it and each other.

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At a glance
  • Categories Content
  • Related fields Content, SEO
  • Difficulty Intermediate

How Topic Cluster Works

Rather than one page trying to cover everything, a cluster spreads a topic across a hub and its spokes, each spoke handling a specific sub-question and linking back to the hub. The internal links tie the pieces into a connected whole. It is the structural way to show an engine that your site covers a subject in real depth.

Why Topic Cluster Matters

AI engines, working through query fan-out, pull from across a topic, not a single page. A well-built cluster gives them strong content for many sub-questions and signals genuine authority on the subject. A glossary like this one is itself a cluster.

Frequently Asked Questions

  • What is the difference between a topic cluster and topical authority?

    The cluster is the structure you build. Topical authority is the credibility that structure earns you.

  • How many pages make a cluster?

    There is no fixed number. Enough to cover the subject's real sub-questions, all interlinked around a central page.

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