Content
Topic Cluster
A topic cluster is a group of related pages covering one subject in depth, organised around a central pillar page and linked together.
The structure signals topical authority to search engines and helps users navigate a subject fully. For example, a pillar on "SEO" linking to clusters on technical SEO, link building, and content forms a cluster. It is a core way to demonstrate expertise across a theme.
Clusters can cannibalise themselves when the supporting pages are too close together. Two articles targeting near-identical questions will split links and rankings, and Google will pick one arbitrarily and often change its mind. Before adding a page, check which existing page already ranks for the query, and if one does, extend it instead of writing alongside it. The internal linking also has to be deliberate, not reciprocal by default. Supporting pages should link to the pillar with descriptive anchors, and the pillar should link out selectively, not to everything in the cluster.
Example
A hosting company builds one pillar page on WordPress speed, then eight supporting pieces: image compression, caching plugins, PHP versions, database cleanup, each linking to the pillar and to each other. Google starts treating the site as an authority on the whole topic: within a quarter, the domain ranks for 340 speed-related queries, most of them never individually targeted.
Frequently asked questions
- Do topic clusters actually improve rankings?
- They help when built properly, mainly through internal linking and comprehensiveness. Covering a subject in genuine depth across linked pages signals expertise and captures more long-tail queries. Publishing thin pages just to have a cluster achieves nothing.
- How many pages does a topic cluster need?
- However many the subject genuinely warrants, typically a pillar page plus five to fifteen supporting pages. The test is whether each page answers a distinct question someone actually asks, not whether you hit a target number.
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