Topic clusters, defined
A topic cluster is a group of interlinked pages about one subject. The pillar page targets the broad topic and summarises every part of it. Each cluster page targets one subtopic or question in depth. The pillar links to every cluster page, and each cluster page links back.
- One page per search intent: the cluster is a plan for covering a topic without duplicates.
- Links do the work: Google uses them to find pages and to understand how they relate.
- There is no topical authority score, no required word count and no need for exact-match anchors.
- A keyword clustering tool gives a first draft; checking the search results decides the final plan.
HubSpot popularised the model in a 2017 report by Mimi An, at a time when most content plans were lists of keywords, each with its own blog post. The result on many sites was dozens of thin articles chasing slight variations of the same query and competing with each other. The cluster model flips the unit of planning from the keyword to the topic.
You will also see the same idea called a content hub or a hub-and-spoke structure. The names differ; the structure is the same.
The Anatomy of a Topic Cluster
The pillar page
The broad overview. It targets the head term, answers the main question directly, and gives each subtopic a short section that ends in a link to its dedicated page. Readers who only need the overview get it; readers who need depth know where to go.
The cluster pages
Each one answers one specific question or task completely, usually a longer, more specific query than the pillar's. It links back to the pillar, and to sibling pages where they genuinely help.
The links
Plain, crawlable links with descriptive anchor text, placed where the reader would want them. They are what turns a set of articles into a cluster.
Why Topic Clusters Help
Links help Google find and understand pages. Google's link guidance says it uses links as a signal when determining the relevancy of pages and to find new pages to crawl, and that every page you care about should have a link from at least one other page on your site. A cluster guarantees that for every page in it.
Structure shows how pages relate. Google's SEO starter guide recommends organising a site logically because it helps search engines and users understand how pages relate to the rest of the site. A pillar with clearly linked subtopics is that organisation at the level of one subject.
Planning by topic prevents cannibalization. When every keyword is mapped to one page before writing starts, you stop publishing a third article on a question two existing articles already half answer. That is often the biggest gain on an established site.
Readers stay on the subject. Someone who lands on a narrow page can move to the overview and the next step without going back to the search results. The pillar becomes the natural page to link to when other sites cite the topic.
A Worked Cluster Plan
An accounting software company wants to own the topic of small business bookkeeping. Here is the cluster it plans. The queries show the kind of target each page gets; check volumes and the current results for your own market.
Illustrative example
| Page | Role | Example target query | Intent |
|---|---|---|---|
| Small business bookkeeping: the complete guide | Pillar | small business bookkeeping | Broad overview |
| How to set up a chart of accounts | Cluster | chart of accounts for small business | How-to |
| Cash vs. accrual accounting | Cluster | cash vs accrual accounting | Comparison |
| How to reconcile a bank account | Cluster | bank reconciliation | How-to |
| Monthly and yearly bookkeeping checklist | Cluster | bookkeeping checklist | Template |
| Bookkeeping vs. accounting | Cluster | bookkeeping vs accounting | Definition |
| When to hire a bookkeeper | Cluster | hire a bookkeeper | Decision |
| Best bookkeeping software for small businesses | Cluster | bookkeeping software for small business | Commercial |
Two decisions shaped this plan. First, the keyword list had both “bank reconciliation” and “how to reconcile a bank statement”. A search for each returned largely the same pages, so they share one cluster page instead of getting two. Second, the company already had two old posts on cash and accrual accounting. The stronger one became the cluster page and absorbed the best of the other, which now redirects to it.
The commercial page (“best bookkeeping software”) belongs in the cluster because people researching bookkeeping eventually compare tools, but it is written for that decision and does not try to rank for the how-to queries.
The linking map
| From | To | Where on the page | Example anchor |
|---|---|---|---|
| Pillar | Every cluster page | In the section that summarises each subtopic | "how to reconcile a bank account" |
| Cluster page | Pillar | Near the top or where the broader context helps | "our guide to small business bookkeeping" |
| Cluster page | Related cluster page | Where one task depends on the other | "the monthly bookkeeping checklist" from the reconciliation page |
| Cluster page | Product or sign-up page | Only where it is the natural next step | "try the reconciliation feature" |
Our guide to internal linking best practices covers anchor text and link placement in more depth.
How to Build a Topic Cluster in Seven Steps
- 1
Pick a topic you can cover completely
Choose a subject your customers care about and your business can speak to with real expertise. Google's helpful content guidance asks whether a site has a primary purpose or focus; a cluster is that focus made visible.
- 2
Collect the subtopics
Start with the queries you already get in Search Console for related pages, then add keyword research, the questions in search results, what competing guides cover and what customers ask your support team. Ahrefs suggests the contents of the topic's Wikipedia article as a quick outline.
- 3
Group the keywords by intent
Paste the list into a clustering tool for a first grouping, then check the borderline cases by hand: if the same pages rank for two keywords, they usually belong on one page. If the results are different, they need different pages.
- 4
Map what you already have
Assign each group to an existing URL or to a new page. Where two existing pages target the same group, plan to merge them and redirect one, before you write anything new.
- 5
Write the pillar
Cover the whole topic at overview depth, with a short section for each subtopic that links to its page. It should answer the broad query on its own. There is no word count to hit.
- 6
Write or upgrade the cluster pages, and link them
Each page answers one intent fully. Link it back to the pillar and to related cluster pages where that helps the reader, with descriptive anchor text. Make sure every page is linked from at least one other page.
- 7
Measure the cluster as a group
In Search Console, filter the Performance report to the cluster's URLs and track clicks, impressions and the queries each page ranks for. Watch for two of your pages appearing for the same query: that is a sign the plan needs a merge.
Using a topic cluster generator
Our free keyword clustering tool takes a pasted keyword list or a seed keyword, groups the keywords by the words they share, and suggests a pillar keyword and supporting pages for each group. It runs in your browser with no login, and exports to CSV. Word-based grouping is fast and good for a first pass, but it cannot see intent: two keywords with different words can want the same page, and two similar ones can want different pages. Use step 3 to settle those cases. For more on planning the keyword side, see modern keyword research and understanding search intent.
What Topic Clusters Do Not Do
Much of the advice around clusters goes further than the evidence. Five common claims, checked against Google's documentation:
"Clusters earn a topical authority score from Google"
Google has not published a topical authority score for websites. Its documented topic authority system, announced in 2023, helps identify expert sources for news queries in specialised areas. Build clusters because they make your coverage complete and easy to navigate, not to unlock a hidden metric.
"A pillar page needs thousands of words"
Google's helpful content guidance is explicit that it has no preferred word count. A pillar is as long as a complete overview of the topic needs to be, and no longer.
"Every link should use the exact keyword"
Google asks for anchor text that is descriptive, reasonably concise and relevant, and warns against cramming keywords into it. Vary anchors the way a person writing naturally would.
"More cluster pages is always better"
Pages that split one intent across several URLs compete with each other. Google's guidance also flags producing lots of content in the hope that some of it performs. Cover each intent once, well.
"Cluster pages must live in one folder"
Not for rankings. Google's starter guide says that on sites with more than a few thousand URLs, grouping similar topics in directories can help it learn how often each section changes. It is useful for large sites and for your own reporting, not a requirement.
If two pages in a cluster already compete for the same query, our guide to keyword cannibalization shows how to confirm it and which page to keep.
Plan the cluster from the queries you already get
Murkuz connects your Search Console, Analytics 4 and Bing Webmaster data to Claude or ChatGPT. Keyword_Rankings lists what you already rank for across Google and Bing, Live_Cannibalization finds your own pages competing for the same query, and Keyword_Ideas suggests related keywords and questions for the gaps. It reads your data; the plan and the pages are yours. See the Search Console connector.
Further reading
The most useful material on topic clusters we found, starting with Google's own documentation. Each one was read in full before it was added here.
Official docsGoogle Search Central
SEO Starter Guide: The BasicsThe sections on organising your site and grouping topically similar pages explain what structure actually does for Google, and the myth list is a useful check on keyword-driven habits.
Official docsGoogle Search Central
Link best practices for GoogleHow Google uses links to find pages and judge relevance, what makes a link crawlable, and how to write anchor text without stuffing keywords. The rulebook for a cluster's internal links.
Official docsGoogle Search Central
Creating helpful, reliable, people-first contentThe self-assessment questions on focus and on producing lots of content in the hope some of it ranks are the best counterweight to building clusters for volume instead of for readers.
ArticleHubSpot, Mimi An
Topic clusters: The next evolution of SEOThe current version of the 2017 HubSpot report that popularised topic clusters, with a five-step process from choosing core topics to internal linking.
GuideAhrefs, Jake Sheridan
How to Build a Topic Cluster in 10 MinutesThree real clusters taken apart, a fast way to find subtopics, and a sensible answer to how many pages a cluster needs: enough to cover the topic, not so many that they cannibalise each other.
Video and articleMoz (Whiteboard Friday), Chima Mmeje
How To Do Comprehensive Research for Your Topic ClusterA research workflow for a cluster that starts from the audience, not a keyword list, and pulls in sources beyond keyword tools.
Frequently Asked Questions
What is a topic cluster?
A topic cluster is a group of pages on one subject, connected by internal links: one broad pillar page that covers the whole topic, and several cluster pages that each cover one subtopic in depth. The pillar links to every cluster page and each cluster page links back, so readers and search engines can see how the pages relate.
What is a pillar page?
A pillar page is the hub of a topic cluster. It targets the broad topic, gives a complete overview of it, and links to a dedicated page for each subtopic that deserves more depth. A good pillar page answers the main question on its own; it is not just a list of links.
What is the difference between pillar pages and topic clusters?
The pillar page is one page; the topic cluster is the whole group. The cluster includes the pillar, the subtopic pages around it, and the links that connect them. Ahrefs notes that topic clusters, content hubs and pillar pages are used to describe basically the same idea.
How many pages should a topic cluster have?
There is no fixed number. HubSpot suggests picking a core topic broad enough to support 20 to 30 supporting articles, while Ahrefs says there is no minimum or maximum. The useful rule is one page per distinct search intent within the topic: enough pages to cover it fully, and never two pages chasing the same query.
What is a topic cluster generator?
A topic cluster generator is a tool that groups a list of keywords into clusters and suggests which keyword should anchor the pillar page and which should become supporting pages. Murkuz has a free keyword clustering tool that does this in your browser without a login. Treat the output as a first draft: check that keywords grouped together really return the same kind of results before you plan one page for them.
Do topic clusters build topical authority?
Topical authority is an industry term for covering a subject thoroughly enough that readers and search engines see your site as a strong source on it. Google has no published topical authority score for websites; its documented topic authority system concerns news. What Google does document is that links help it find and understand pages and that a logical structure helps it see how pages relate, which is what a well-built cluster provides.
How should pillar and cluster pages link to each other?
Link the pillar to every cluster page from the section that summarises that subtopic, and link each cluster page back to the pillar where the context fits. Link cluster pages to each other when one genuinely helps with the other. Use descriptive anchor text and vary it naturally; Google warns against cramming keywords into anchor text.