A topic cluster is a group of pages built around one subject: a broad pillar page (the hub) that gives the overview, and a set of cluster pages (the spokes) that each answer one narrower question in depth. Every spoke links up to the pillar, the pillar links down to every spoke, and spokes link to each other where it helps the reader.
What is a topic cluster, and how does a pillar page differ from a cluster page?
Take a startup selling accounting software for freelancers. The pillar is “Freelance invoicing: the complete guide”, covering the whole process in 1,500 to 3,000 words. The spokes are specific: “invoice template for freelancers”, “how to chase a late payment”, “invoice numbering rules”, “VAT on invoices for sole traders”.
| Page | Targets | Depth | Links |
|---|---|---|---|
| Pillar | A broad term with wide intent | Overview of every subtopic | To each spoke |
| Spoke | One specific question or long-tail keyword | Full answer to that one question | Up to the pillar, sideways to related spokes |
The word counts are an editorial choice. Google says it has no preferred length: its helpful content guidance lists writing to a particular word count as a warning sign.
Why do topic clusters matter for SEO?
Be clear about what Google says. Google has no “topic cluster” ranking factor and no rule that pillar pages rank better. What it does say supports the method, though:
- Internal links help discovery and meaning. Google’s link guidance says every page you care about should be linked from at least one other page, and that linking to related pages in context helps both readers and Google understand your content.
- Descriptive anchor text tells Google what the target page is about.
- Completeness serves readers. Google’s helpful content questions ask whether your content gives a complete description of the topic and whether readers leave with their goal met.
On top of that, a cluster is a planning tool. It stops a blog from becoming a random pile of posts, shows what is missing and gives each page a clear job. Clusters also tend to be easier to refresh and to expand, because you know where each new post belongs (see content refresh).
How do you build a topic cluster, step by step?
- Choose a topic you can own. Pick a subject close to what you sell, where you have real experience. A cluster needs a dozen good pages, so choose something you can keep writing about.
- List the questions. Use keyword research: the Queries tab in Search Console, autocomplete, People also ask and customer questions. Write each question as a candidate spoke.
- Group by intent. Questions with the same answer become one page. Questions with different intents become different pages (see search intent). Cut anything off-topic.
- Check what exists. Map your current pages to the list. Half the spokes may already exist as old posts that need updating and linking, not rewriting from scratch (see content gap analysis).
- Draft the pillar. Cover every subtopic in a short section with a clear H2, then send the reader to the spoke for detail. Add a table of contents. The pillar should rank for the broad term and act as a map.
- Write the spokes. One main question per page, answered in the first lines, then detail. Each spoke needs a reason to exist that the pillar’s short section cannot satisfy.
- Link both ways. Spokes link to the pillar in the first third of the text, with descriptive anchors (“freelance invoicing guide”, never “click here”). The pillar links to every spoke. Neighbouring spokes link to each other where the reader would want the next step. Use normal
<a href>links Google can crawl (see internal linking). - Reflect it in the structure. Use matching categories or URL folders such as
/invoicing/if they fit, and add breadcrumbs. This is optional, and links matter more than folders. - Publish in order of value. Release the pillar and the three to five highest-intent spokes first, then add the rest on a schedule.
How do you measure whether a cluster works?
Tag each page in your sheet with its cluster. In Search Console, filter the Performance report by a page URL pattern (say, pages containing /invoicing/) and watch it quarterly:
- Total impressions and clicks for the group, not page by page.
- Distinct queries the group shows for: this should grow as spokes are added.
- Pillar position for the broad term.
- Internal link counts from a crawl: no spoke should be an orphan.
- Conversions from cluster pages in GA4 (see GA4 setup).
Judge a cluster after about three months of its pages being indexed.
What mistakes should you avoid?
- Spokes that compete. Two spokes aiming at the same query split signals and confuse Google (see keyword cannibalization).
- A pillar that is only a list of links. It needs real content for its broad query.
- Padding to hit a count. Five great spokes beat fifteen thin ones. Thin pages produced at scale conflict with Google’s spam policy on scaled content abuse.
- Forgetting the links. A cluster without links is just a set of posts.
- Never updating the pillar. When you add a spoke, add it to the pillar the same day.
Where can you learn more?
The Fe/male Switch content ideas generator turns a topic into a list of questions you can sort into spokes. Next steps on SEO100: sharpen your internal linking, then read how semantic SEO and entities shape what a complete topic covers.