What is a topic cluster?
A topic cluster is a set of interlinked pages about one subject, built around a broad pillar page. The pillar gives an overview, and each supporting article, often called a cluster page, answers one narrower question in full.
The term is an SEO community idea rather than a Google one. Ahrefs notes that topic clusters, content hubs and pillar pages are different names for the same pattern, which HubSpot helped popularise with its hub and spoke diagram.
Why do topic clusters matter?
They make your coverage of a subject easy to find and easy to follow. Google finds most new pages through links, and it uses anchor text to understand what the linked page is about, so a tidy cluster tells it clearly which page covers which question.
Clusters also stop you writing the same article twice. When every subtopic has one home, you are far less likely to end up with two pages competing for the same search.
How do you build a topic cluster?
Start from the questions people ask, not from the pages you already have.
- 1Pick one subject your site should be known for, broad enough to have many subtopics.
- 2List the questions and searches people use around it, then group them by what the searcher wants.
- 3Assign each group to a single page. One group becomes the pillar; the rest become cluster pages.
- 4Write or update each cluster page so it answers its question fully.
- 5Link every cluster page to the pillar, link the pillar to every cluster page, and link between cluster pages where it helps the reader.
What does a topic cluster look like?
Here is a small cluster for a site about home coffee.
| Page | Role | Main search it targets |
|---|---|---|
| Home espresso: a complete guide | Pillar | home espresso |
| How to dial in espresso | Cluster page | how to dial in espresso |
| Best grind size for espresso | Cluster page | espresso grind size |
| How to descale an espresso machine | Cluster page | descale espresso machine |
| Single vs double boiler machines | Cluster page | single vs double boiler |
Frequently asked questions
How many articles should a topic cluster have?
There is no fixed number. Small clusters of four to eight pages are common, and the right size is however many distinct questions the subject really has. Splitting one question across several thin pages makes a cluster worse, not better.
Is a topic cluster the same as a content hub?
Mostly, yes. Both describe a central page linked to a set of related, more detailed pages. Some people use “content hub” for the whole collection and “pillar page” for the central page.
Do topic clusters need a special URL structure?
No. Putting cluster pages in one folder can help keep things organised, but the links between the pages are what define the cluster.
Can one article belong to more than one cluster?
It can be linked from more than one cluster, but it should have one clear main topic. If an article fits two clusters equally, it may be trying to answer two questions at once.