Quick answer
A topic cluster is a group of pages on one subject: a pillar page that covers the topic broadly, plus cluster pages that each go deep on one subtopic, all linked to each other. It helps readers find related answers, helps search engines understand how your pages connect, and keeps you from writing several pages that compete for the same search.
In 2015, two members of HubSpot's marketing team, Anum Hussain and Cambria Davies, ran an experiment on their own blog. They grouped related posts around central topics and linked them together more deliberately. The research they presented, "Topics Over Keywords," became the foundation of what's now called the topic cluster model.
A decade later, the idea has spread well beyond HubSpot, and for a simple reason: it matches how people research. Someone planning a roof replacement doesn't ask one question. They ask about cost, materials, timing, permits and insurance, often across several searches. A topic cluster answers all of those in one connected set of pages. This guide shows how to plan one, with a planning sheet you can copy.
What topic clusters and pillar pages are
A topic cluster is a set of linked pages built around one core subject. The pillar page gives the broad overview, and each cluster page answers one specific question in depth, with links running between them.
HubSpot's topic cluster guide, updated June 17, 2026, describes it this way: "Topic clusters organize a group of related content pieces (cluster pages) around one central pillar page." The pillar "covers a broad subject at a high level," while each cluster page addresses a specific subtopic.
The three parts:
- Pillar page: a broad guide to the main topic, such as "Roof replacement: the complete guide."
- Cluster pages: focused pages on single subtopics, such as roof replacement cost or how to choose roofing materials.
- Internal links: every cluster page links to the pillar, the pillar links to every cluster page, and closely related cluster pages link to each other.
Pillar: Roof replacement: the complete guide (/roof-replacement/), linking to every cluster page
- Roof replacement cost/roof-replacement/cost/Links to pillar
- Asphalt vs metal roofing/roof-replacement/materials/Links to pillar
- Signs you need a new roof/roof-replacement/signs/Links to pillar
- Insurance and roof replacement/roof-replacement/insurance/Links to pillar
- Roof replacement timeline/roof-replacement/timeline/Links to pillar
Fictional example. Close siblings, such as cost and materials, also link to each other.
Pillar page vs landing page vs blog post
A pillar page educates broadly, a landing page converts a visitor on one offer, and a blog post answers one question. They work together, but each has a different job.
| Page type | Purpose | Depth | Search intent | Conversion goal |
|---|---|---|---|---|
| Pillar page | Cover a whole topic and connect related pages | Broad overview, links to deeper pages | Informational, early research | Move readers to cluster pages or a service page |
| Landing page | Turn a visitor into a lead or sale | Focused on one offer | Transactional | Form fill, call or purchase |
| Blog post (cluster page) | Answer one specific question in depth | Deep on a narrow subtopic | Informational or commercial | Link back to the pillar or a service page |
For a service business, the service page often doubles as the landing page, and a pillar guide supports it by answering the questions customers have before they're ready to buy. "Pillar content" means the broad, foundational content a cluster is built around.
Why topic clusters help SEO and AI search
Topic clusters help search engines understand which pages on your site belong together and which one is most important. They also help you cover a subject thoroughly without creating several pages that compete for the same search.
Internal links are the mechanism. Google's link best practices state: "Every page you care about should have a link from at least one other page on your site." Google's site structure guidance adds that "As a general rule, the more links a page has to it within a site, the higher the relative importance of the page." A pillar with links from every cluster page signals clearly which page leads on the topic.
It helps readers too. Someone who lands on your cost page from a search can move straight to materials, timelines or insurance without going back to Google, which keeps them on your site and closer to contacting you.
Clusters also reduce cannibalization, where two of your own pages target the same search and drag each other down. Planning one page per question keeps every page's job distinct.
AI search adds another reason. Google's AI Overviews and AI Mode may issue "multiple related searches across subtopics and data sources" to build an answer, according to Google's AI features documentation. A cluster that covers each subtopic with a clear, dedicated page gives Google more chances to find a strong answer on your site for each part of the question. None of this guarantees rankings or citations, but it gives your best answers a clearer path to being found.
How to plan a topic cluster in 6 steps
Plan a cluster in six steps: pick a core topic, research its subtopics, group them by intent, map the URLs, plan the links, and set a publishing order. Do the planning in a spreadsheet before writing anything.
- Pick a core topic tied to a service you sell. Choose a subject broad enough to need several pages but close enough to your business that readers become customers. "Roof replacement" works for a roofer. "Home improvement" is too broad.
- Research the subtopics. Collect the questions people ask about the topic from Google's People Also Ask, autocomplete, related searches, keyword tools and your own customer calls. Our guide to how to do keyword research covers the full process. Aim for a long list at this stage.
- Group by intent, one page per intent. Combine questions that a single page could answer well, and separate those that need their own page. "How much does a new roof cost?" and "Roof replacement cost per square foot" belong together. "Does insurance cover roof replacement?" needs its own page.
- Map URLs and choose the pillar. Decide which page covers the broad topic and give it a short, clear URL, such as /roof-replacement/. Give each cluster page its own URL, ideally nested or clearly related, such as /roof-replacement/cost/.
- Plan the links. Every cluster page links up to the pillar, the pillar links down to every cluster page, and close siblings link to each other. Use descriptive anchor text: Google advises that "Good anchor text is descriptive, reasonably concise, and relevant to the page that it's on and to the page it links to."
- Set a publishing order and owner. Publish the pillar and the two or three most valuable cluster pages first, then add the rest over the following weeks. Give each page an owner and a review date.
Here's how the roofer's plan might look in practice. The pillar, "Roof replacement: the complete guide," goes live first with a short section on each subtopic. The cost and materials pages follow in week two, since they bring the most buying-stage visitors. Insurance, warning signs and timeline pages follow over the next month. As each goes live, the pillar's matching section gets a link to it.
A topic cluster planning sheet you can copy
Copy the table below into a spreadsheet and replace the example rows with your own topic. The example is a fictional roofing company, included to show how the columns work.
| Page | Role | Primary keyword | Intent | URL | Links to | Status |
|---|---|---|---|---|---|---|
| Roof replacement: the complete guide | Pillar | roof replacement | Informational | /roof-replacement/ | All cluster pages, roofing service page | Planned |
| How much does a new roof cost? | Cluster | roof replacement cost | Commercial | /roof-replacement/cost/ | Pillar, materials page, service page | Planned |
| Asphalt vs metal roofing | Cluster | best roofing material | Commercial | /roof-replacement/materials/ | Pillar, cost page | Planned |
| Signs you need a new roof | Cluster | signs you need a new roof | Informational | /roof-replacement/signs/ | Pillar, insurance page | Planned |
| Does insurance cover roof replacement? | Cluster | roof replacement insurance | Informational | /roof-replacement/insurance/ | Pillar, signs page | Planned |
| How long does a roof replacement take? | Cluster | how long does a roof replacement take | Informational | /roof-replacement/timeline/ | Pillar, cost page | Planned |
A few tips for using the sheet:
- Keep one primary keyword per row. If two rows share a keyword, merge them.
- Use the "Links to" column as a checklist when you publish, so no page goes live without its links.
- Add a "Last reviewed" column once the cluster is live, so you can see at a glance which pages need a refresh.
How many cluster pages do you need?
You need as many cluster pages as there are distinct questions that each deserve their own answer. There's no ideal number. A small service cluster might need four pages, while a broad topic could need twenty.
The test for each potential page is simple: would someone search for this question on its own, and would the answer be too long or too different to fit inside another page? If yes, it gets its own page. If a question can be answered in a paragraph on an existing page, add it there instead.
For example, "How long does a roof replacement take?" might deserve its own page, since people search it on its own and the answer covers weather, crew size and roof type. "Do roofers work in the rain?" probably fits as a short section on that same timeline page.
Start small. A pillar plus three or four strong cluster pages is a complete, useful cluster. Add pages as you find new questions in Search Console, customer calls and People Also Ask, rather than trying to publish everything at once.
Topic clusters for local and service businesses
For a local service business, the service page usually makes the best pillar, with area pages and FAQ posts as its cluster. That keeps the cluster tied directly to what you sell.
A typical local cluster might look like this:
- Pillar: your main service page, such as "AC repair in Phoenix."
- Area pages: one page for each area you genuinely serve, such as Mesa, Tempe and Scottsdale, each showing work done in that town and reviews from customers who live there.
- FAQ and guide posts: answers to the questions customers ask, such as "Why is my AC blowing warm air?" or "How much does AC repair cost in Phoenix?"
Be careful with area pages. Near-identical city pages that only swap the town name can count as doorway pages under Google's spam policies. Each area page needs its own substance. Our guide to local SEO for small businesses covers how to build area pages that hold up.
A strong area page for Mesa would include AC repairs completed in Mesa neighborhoods, reviews from Mesa customers, typical response times to the area and a note on common issues there, such as older units in certain developments. It then links to the main AC repair pillar and to the most relevant FAQ posts.
Common topic cluster mistakes
Most clusters underperform for the same handful of reasons. Check your plan against these before you publish.
Avoid these:
- Writing for search engines first: Google's helpful content guidance asks, "Is the content primarily made to attract visits from search engines?" Pages built only to fill a cluster slot rarely help readers.
- Overlapping pages: two cluster pages answering the same question compete with each other.
- Orphan pages: a cluster page with no links pointing to it is hard for readers and Google to find.
- Generic anchors: "click here" and "read more" tell nobody what the linked page covers.
- A pillar that lists links and little else: the pillar should give a genuinely useful overview, with links that add depth.
How to measure and maintain a cluster
Measure a cluster as a group, using Search Console to track impressions, clicks and positions for all its pages together, and maintain it with a quarterly review. Clusters improve over time when they're kept current.
Measure as a group. In Search Console's Performance report, filter pages by the cluster's URL folder, such as /roof-replacement/, to see the whole cluster's performance at once. Watch total impressions and clicks, and check which cluster pages bring visitors to the pillar and service page.
Check internal links. Crawl the cluster quarterly to confirm every page still links to the pillar and the pillar links to every page, especially after site changes.
Refresh outdated pages. Update prices, dates, examples and statistics at least once a year, and add new cluster pages for questions that come up.
Watch for cannibalization as the cluster grows. If two pages start appearing for the same search in Search Console and swapping positions, merge them or sharpen each page's focus so their jobs stay distinct. Our guide to how to update old blog posts covers how. For on-page details on each cluster page, see our on-page SEO checklist.
For the bigger picture on planning content, read our content marketing strategy for small businesses, and for how AI search works, our guide to what generative engine optimization is.
Topic cluster FAQs
What are topic clusters in SEO?
Topic clusters are groups of linked pages on one subject: a broad pillar page and several cluster pages that each cover one subtopic in depth. The links between them help readers find related answers and help search engines understand how the pages connect and which one leads on the topic.
What is the difference between a pillar page and a landing page?
A pillar page gives a broad overview of a topic and links to deeper pages, serving readers in the research stage. A landing page focuses on converting visitors on a single offer, such as booking a call or requesting a quote. Pillars educate; landing pages convert.
Can you give an example of a topic cluster?
A roofing company might build a pillar page on roof replacement, with cluster pages on cost, roofing materials, signs you need a new roof, insurance coverage and project timelines. Each cluster page links to the pillar, the pillar links to each page, and related pages link to each other.
What does pillar content mean?
Pillar content is the broad, foundational content a topic cluster is built around, usually a thorough guide to one subject. It covers the main points at a high level and links to cluster pages that go deeper on each subtopic.
Do topic clusters help with AI search?
They can. Google's AI features may run several related searches across subtopics to build an answer. A cluster with a clear page for each subtopic gives Google more chances to find a strong answer on your site, though no structure guarantees citations.
Sources
- HubSpot, "Topic clusters: The next evolution of SEO," updated June 17, 2026: https://blog.hubspot.com/marketing/topic-clusters-seo
- Google Search Central, "Link best practices for Google," updated December 10, 2025: https://developers.google.com/search/docs/crawling-indexing/links-crawlable
- Google Search Central, "Help Google understand your ecommerce site structure," updated December 10, 2025: https://developers.google.com/search/docs/specialty/ecommerce/help-google-understand-your-ecommerce-site-structure
- Google Search Central, "AI features and your website," updated December 10, 2025: https://developers.google.com/search/docs/appearance/ai-features
- Google Search Central, "Creating helpful, reliable, people-first content," updated October 5, 2026: https://developers.google.com/search/docs/fundamentals/creating-helpful-content