SEO glossary

Topic cluster

Definition

A topic cluster is one pillar page plus the supporting pages that link to it, each covering a distinct slice of the topic. The planning step that decides whether it works is assigning exactly one search intent per page before anyone writes. Do that badly and the siblings compete with each other for the same query.

Updated 26 July 2026 · Written by the Last Agency team · See what SEO actually costs

The short version

  • Clusters don't fail during writing. They fail in the plan, when two pages are given the same job and nobody notices until both stop ranking.
  • One page, one intent. Write the intent next to the title in the plan, in a sentence describing the person searching.
  • Six to fifteen pages is a workable cluster. Under six it's a page with links; over twenty it's usually two clusters pretending to be one.
  • Publish two or three commercial spokes before the pillar, so the pillar has something real to link to on the day it goes live.

The structure, in one paragraph

One pillar page covers the topic broadly and links out to every supporting page. Each supporting page — a spoke — covers one narrow slice properly, and links back up to the pillar. That's the whole model. Hub and spoke, borrowed from airline route maps, which is a better metaphor than it sounds: the hub exists so the spokes connect.

What the structure buys you is threefold. Each page gets to match one query type precisely instead of hedging. Internal links concentrate rather than scatter. And a search engine reading the cluster sees a site that covers the subject rather than a site that once wrote about it — which is the practical route to topical authority.

The planning step everyone skips

Most cluster plans are a list of twelve titles. Titles aren't a plan, because two titles can describe the same search. "Dental implant cost" and "Are dental implants worth the money" look like different articles and are frequently the same query with different words on it.

So write the intent, not the title. One sentence per page, describing the person typing and what they need to leave with. If two sentences describe the same person in the same moment, you have eleven pages, not twelve. Do this before a single brief goes out and you've prevented the expensive version of the problem.

Here's what a real one looks like — a Bangalore dental clinic building out implants.

A 12-page implant cluster, with one distinct intent per page.
PageThe intent it owns
Dental implants in Bangalore (pillar)Broad commercial — someone choosing where to get it done
What is a dental implantInformational — first-time researcher, no vocabulary yet
Dental implant cost in BangaloreCommercial investigation — comparing prices before enquiring
Single tooth implantProduct-specific — one missing tooth, wants that case explained
Full mouth implants and All-on-4Product-specific — complete restoration, much higher value
Implants vs bridgesComparison — deciding between two treatments a dentist offered
Implants vs denturesComparison — older patient, entirely different objections
The implant procedure, step by stepReassurance — anxious patient wanting the sequence and the timeline
Recovery and aftercarePost-decision — already booked, searching at 11pm
Am I a candidate for implants?Qualification — bone density, diabetes, smoking, age
Implant cost, insurance and EMI in IndiaFinancial objection — can afford it monthly, not upfront
Implant brands and materialsTechnical comparison — informed buyer checking what you use

The linking pattern

Links are what convert twelve files into a cluster. The pattern is simple enough to hand to a writer as a rule.

  1. Every spoke links up to the pillar, once, with a consistent anchor. That's the vote that says which page is the hub.
  2. The pillar links down to every spoke, from the section that summarises it, using the spoke's own subject as the anchor — "implant recovery timeline", not "dental implants".
  3. Spokes link sideways only where a reader would actually want it. Cost to EMI, yes. Cost to recovery, no.
  4. Never link two spokes that compete for the same query family. If you find yourself wanting to, that's the two-page test failing late.
  5. Fix the anchors when you consolidate. Redirecting a merged page and leaving forty internal links pointing at the old URL wastes the consolidation you just paid for.

Size, order, and why this stops cannibalisation

Six to fifteen pages is the workable range. Fewer than six and the pillar has nothing to route to. More than twenty and it's usually two subjects sharing a folder — split it, and give each half its own hub.

On order, we go against the common advice. Most plans build the pillar first, which produces a hub page linking to nothing for six weeks. Build two or three of the clearly commercial spokes first — the cost page, the main comparison, the highest-value treatment — then the pillar, then the informational spokes. The commercial pages pay for the rest of the cluster while it's being built, and the pillar launches into a cluster that already exists.

The cannibalisation argument is the real reason to do any of this. When two of your pages target one query, Google has to choose. It alternates between them, neither settles, your internal links split across both, and any external link you earn lands on whichever one the writer happened to find. One intent per page removes the choice entirely — see keyword cannibalisation for what the alternative costs, and our post-mortem for what unwinding it looks like.

The cluster also fails quietly if nobody owns it after launch. Six months in, someone writes a new post that overlaps with page four, because the plan lives in a spreadsheet nobody opens. Put the intent sentence in the CMS next to the page, where the next writer will actually see it.

Related questions.

How many pages should a topic cluster have?

Six to fifteen in most cases. The number should come from how many distinct buyer intents exist in the topic, not from a content quota. Fewer than six and a pillar isn't earning its place; more than twenty usually means you're looking at two clusters that should be split and given separate hubs.

Do topic clusters still work in 2026?

The linking structure and the discipline of one intent per page still work, because both are about clarity rather than a loophole. What no longer works is treating cluster count as the goal and publishing thin pages to complete a map — that's the behaviour Google's scaled content abuse policy targets.

Should I write the pillar page first?

We'd publish two or three commercial spokes first, then the pillar, then the rest. A pillar that goes live linking to nothing is a hub with no routes, and the commercial pages start earning while the cluster is still being built. Either order works; publishing the pillar alone and stopping does not.

How do topic clusters prevent keyword cannibalisation?

By assigning each query family to exactly one page before anything is written, so Google never has to choose between two of your URLs. Cannibalisation is almost always a planning failure that surfaces months later as two pages swapping positions and neither one settling.

What's the difference between a topic cluster and topical authority?

A topic cluster is a structure — one pillar, several spokes, a defined linking pattern. Topical authority describes the outcome of covering a subject completely and credibly. Clusters are how you build towards it; they're not the same thing, and one well-built cluster doesn't make you an authority on the whole category.

How long before a topic cluster starts ranking?

Individual long-tail spokes often pick up impressions within four to eight weeks. The pillar and the competitive commercial pages take longer, typically three to six months, and longer again on a site with a weak link profile. The compounding effect — new pages ranking faster than earlier ones — shows up across quarters.

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