Topic cluster
A pillar page plus the supporting posts that all link back to it, signaling topical authority to search and AI engines.
In depth
What it really means
A topic cluster is a structure: one pillar page covering a broad topic, surrounded by posts that each go deep on a subtopic and link back to it. Together they tell search engines you cover the whole subject rather than one keyword.
It is the practical form of topical authority. Instead of unconnected posts, the cluster interlinks so authority flows up to the pillar and relevance flows out to the spokes.
Sizing and build sequence
A cluster needs a pillar plus 6 to 20 spokes, each with a distinct search intent.
Build in this order, which most teams get backwards:
Map the subtopics first. List every question a buyer asks about the topic across the journey. Aim for 15 to 25 before filtering.
Check demand and intent per subtopic. Cut anything with no volume or an intent already served elsewhere on your site.
Publish three spokes. Cheapest way to validate the topic pulls traffic at all.
Write the pillar. Now you know the real subtopics and have links waiting.
Fill to six or more spokes, then wire everything.
The cluster health check
Run this quarterly. A healthy cluster passes all four:
Every spoke links up to the pillar with descriptive anchor text.
The pillar links down to every spoke.
No two spokes rank for the same query.
The pillar outranks all its own spokes for the head term.
The fourth is the one that fails most often, and it usually means a spoke has accidentally become the better page. Merge it into the pillar or narrow it.
Pros & cons
Pros
- Builds topical authority faster than the same number of isolated posts.
- Internal links spread ranking signals across the set instead of stranding them.
- Gives writers a map, which ends the pattern of publishing whatever seemed interesting.
- Serves conversational AI search well, since follow-up questions map onto spokes.
Cons
- Requires planning before writing, which delays the first publish date.
- A missing spoke leaves a visible hole a competitor fills.
- Interlinking degrades as posts are added unless someone owns it.
- Commits you to a topic for a year or more, which forecloses other options.
The mistake people make
Building a second cluster before the first is finished. A cluster at 60% coverage competes with nothing, because the gaps are exactly where competitors rank and where AI engines find someone else to cite. Two complete clusters beat five half-built ones, every time, and the half-built ones are the more common outcome by a wide margin.
Best practices
- Start from the pillar concept, then map 15 to 25 subtopics before writing anything.
- Give every spoke a link up and the pillar a link down to each.
- Match each spoke to a distinct intent so they do not cannibalize each other.
- Cross-link spokes where topics genuinely overlap.
- Finish the cluster before starting the next one.
- Re-audit the internal links quarterly.
FAQs
How many posts make a topic cluster?
A pillar plus roughly 6 to 20 supporting posts, enough to cover the subtopics a buyer actually asks about.
Topic cluster vs pillar page?
The pillar is one page. The cluster is the pillar plus its spokes and the links between them.
Do clusters still matter with AI search?
More than before. Conversational search moves through follow-up questions, and a cluster has a page ready for each one.
How do I stop spokes competing?
Give each a distinct search intent and keyword. If two overlap, merge them and redirect.
Where does the cluster start?
With the subtopic map. Publish two or three spokes to validate demand before committing to the pillar.
Keep reading
Related on LymLyt
Beyond LymLyt
Further reading
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