What Is a Topic Cluster? (Pillar + Spoke, Explained)
A topic cluster is a pillar page plus supporting pages on one theme that link to each other. See how the hub-and-spoke model works, with a real 14-page example.
A topic cluster is a pillar page plus a set of supporting pages that all cover one theme and link to each other. The pillar targets the broad term; the supporting pages target specific sub-topics and link back to the pillar. Together they tell a search engine that the site covers a subject in depth, not in one thin post.
This page explains the topic cluster model and shows a real one. It sits inside the B2B keyword research workflow, which is the method for building a cluster from scratch.
The quick answer
A topic cluster has three parts:
- Pillar (hub): one broad page covering the whole theme at a high level.
- Spokes: focused pages, each targeting one specific intent or sub-topic.
- Internal links: every spoke links to the pillar, the pillar links to every spoke, and related spokes link to each other.
The structure — not any single page — is what signals topical authority.
Why clusters work better than scattered posts
A single page can rank for one term. A cluster ranks for a whole theme because the internal links pass relevance between pages and show search engines the relationship between them. It also helps readers: someone who lands on a narrow spoke can move up to the pillar for context or sideways to a related spoke.
There is a practical benefit too. When you organize by cluster, you stop writing duplicate pages, because every new page has a defined slot and one intent. Two pages chasing the same intent is keyword cannibalization — clusters prevent it by design.
One seed, fourteen pages
A cluster does not have a “correct” size — the number of pages comes from the number of distinct intents, not a target. In one antenna build, the seed patch antenna resolved into a 14-page cluster:
| Layer | Pages |
|---|---|
| Pillar | patch antennas (the category hub) |
| Commercial | patch antenna manufacturer |
| Product | gps patch antenna · rhcp patch antenna |
| Application | patch antenna for drones · applications |
| Supporting blogs | design · gain · bandwidth · how to choose · rhcp vs lhcp · pros & cons · radiation pattern · basics |
Each page maps to exactly one search intent, and each links back to the pillar. That link structure is what signals depth, instead of one isolated post trying to rank for everything. The full build is in the B2B topic cluster example.
Pillar vs. spoke: which to build first
The instinct is to write the pillar first. On a new site that is usually backwards: the pillar targets the broadest, hardest term, so it is the least winnable page early. Build the winnable spokes first, then the pillar last, and connect them. The reasoning behind that order is in the keyword priority matrix, and the wiring is in internal linking strategy.
How to plan a cluster
You do not design a cluster by guessing sub-topics. You build it from validated keywords: find seeds, validate intent on the SERP to decide how many pages, then map one intent to one URL. That map is the cluster. The steps are keyword mapping, and the order to publish them is the content production plan.
Common mistakes
- Forcing a fixed page count. Let distinct intents decide the size, not a “10 spokes per pillar” rule.
- A pillar with no real spokes. A lone pillar is just a long post; the supporting pages are what make it a cluster.
- Spokes that never link to the pillar. Without the links, it is a folder of posts, not a cluster.
- Overlapping spokes. Two spokes on the same intent compete with each other instead of supporting the pillar.
FAQ
What is a topic cluster in SEO?
A topic cluster is a group of pages on one theme — a broad pillar page plus focused supporting pages — that link to each other so search engines see the site covers the subject in depth.
What is the difference between a pillar page and a cluster page?
The pillar covers the whole theme broadly and targets the head term; cluster (spoke) pages each cover one narrow sub-topic and link back to the pillar.
How many pages should a topic cluster have?
As many as the theme has distinct search intents. One real cluster had 14 pages because the SERP showed 14 intents — the number is an output, not a target.
Do internal links really matter for clusters?
Yes. The links are what make a set of pages a cluster; they pass relevance between pages and signal the topical relationship to search engines.
Conclusion
A topic cluster is a pillar plus supporting pages on one theme, tied together with internal links. It ranks for a subject rather than a single term, prevents duplicate pages, and helps readers navigate. Build the winnable spokes first, add the pillar, and wire the links — and let distinct intents decide how big the cluster gets.
Next, build your own from validated keywords with keyword mapping, or study a finished one in the B2B topic cluster example.
Written by Taylor Yang. More on the method and the author on the about page.
Free template: the keyword map and content brief templates used to plan clusters.
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