Quick answer: a topic cluster is a group of posts on one subject. A broad pillar page covers the whole subject at a high level, and several narrower spoke posts each answer one specific question in depth. The pillar links to every spoke, and every spoke links back to the pillar and to one or two siblings. Plan the cluster on paper first: pick a pillar topic your audience cares about, list 8 to 12 distinct questions under it, check each against your existing posts, then publish the pillar first and the spokes after it.
Many blogs grow one post at a time with no plan beyond the next idea. After a year or two, the archive becomes a pile of loosely related articles that barely link to each other. Readers struggle to find related posts, and search engines get a muddled picture of what the site covers.
Topic clusters fix that by grouping content around a few core subjects. This guide explains how the model works, how to plan a cluster from scratch, how to link it, and how to fold older posts into it. It is one of the planning chapters in our guide on how to start a blog that makes money, which is itself built as a pillar page with spokes around it.
What a Topic Cluster Is
The idea is simple. Pick a broad subject. Write one comprehensive page that introduces every major part of it, then write separate, more detailed posts for each part. Connect them with links so a reader can move between the overview and the details in either direction.
Three pieces make up every cluster:
- The pillar page: a long, broad guide that covers the whole topic and points to deeper posts
- Spoke posts: focused articles, each answering one question or covering one subtopic in depth
- Internal links: the pillar links out to every spoke, each spoke links back to the pillar, and closely related spokes link to each other
Pillar pages often run 3,000 words or more because they touch every part of a topic. Spokes vary in length depending on the question. Length is not the goal, though. The goal is that the pillar gives a complete map and each spoke fully answers its own question.
Why the model helps
For readers, a cluster makes a site easier to use. Someone who lands on a narrow post can step up to the overview, and someone reading the overview can drill down to the detail they need.
For search engines, clear links and consistent topics make a site easier to understand. Google’s SEO Starter Guide recommends organizing a site so related content is grouped together and linking pages with descriptive anchor text. Google’s link best practices documentation explains that Google uses links to find pages and to understand their context. A cluster puts both ideas into practice. Google has not said that clusters are a ranking factor in themselves, so treat the model as a way to build a better site rather than a trick.
Choosing Pillar Topics
Good pillar topics sit at the center of what a blog is about. They are broad enough to hold 8 to 15 distinct spoke questions and narrow enough to cover thoroughly on one page.
A few tests help when choosing:
- Does the topic connect directly to what your audience wants to achieve?
- Can you list at least eight separate questions people ask about it?
- Does it tie to how the site earns money, through ads, digital products, services or another model?
- Do you have, or can you build, real knowledge of it?
- Do you already have a few posts that could fit underneath it?
A small blog usually needs only three to five pillars to start. Each pillar becomes a section of the site that grows over time. Our guide to choosing a blog niche is a good starting point if the core subjects are not settled yet.
Too broad, too narrow, about right
“Money” is too broad for one pillar; no single page can cover it. “How to open a high-yield savings account at one specific bank” is too narrow, since it is really a single spoke. “Budgeting for beginners” sits in the useful middle: broad enough for a dozen spokes on methods, apps, irregular income and sinking funds, but focused enough for one solid guide.
Mapping Spokes by Search Intent
Once the pillar topic is set, list the questions underneath it. Each spoke should answer one distinct question with one dominant search intent. Two spokes that answer the same question compete with each other, a problem often called keyword cannibalization.
Good sources for spoke ideas include:
- The “People also ask” box and related searches on Google for the pillar’s main term
- Autocomplete suggestions as you type the topic into Google or YouTube
- Questions readers send by email or leave in comments
- Forum and community threads where your audience asks for help
- Free keyword tools, covered in our guide to free keyword research for beginner bloggers
Sort the list into intent groups. How-to questions become step-by-step guides. “What is” questions become explainers. “X vs Y” questions become comparisons. Matching each spoke to the right format keeps the cluster from turning into a dozen near-identical posts.
A sample cluster map
Here is how a hypothetical budgeting cluster might look on paper:
- Pillar: Budgeting for Beginners: Methods, Tools and a First-Month Plan
- Spoke: The 50/30/20 Rule Explained With Examples
- Spoke: Zero-Based Budgeting: How It Works Step by Step
- Spoke: Budgeting on an Irregular Income
- Spoke: Sinking Funds: What They Are and How to Set Them Up
- Spoke: Budget Apps vs Spreadsheets: Which Fits You
- Spoke: How to Cut Grocery Spending Without Coupons
- Spoke: How to Build an Emergency Fund on a Tight Budget
- Spoke: Budgeting as a Couple: Ways to Split Money
Each line answers a different question. Every spoke can link back to the pillar naturally, and several have obvious siblings, such as the emergency fund and sinking fund posts.
Linking Rules That Keep a Cluster Tidy
Links are what turn a set of posts into a cluster. Consistent rules make the work faster and stop links from becoming random.
- The pillar links to every spoke, both inline where a topic comes up and in a “Related guides” list near the end
- Each spoke links to the pillar early in the post, ideally within the first few paragraphs
- Each spoke links to one or two closely related spokes where it helps the reader
- Anchor text describes the destination; Google’s documentation recommends descriptive anchor text over generic phrases like “click here”
- Vary anchors naturally rather than repeating the exact same phrase on every page
- Link only to published pages that load correctly, and check old links periodically
Keep the total reasonable. A spoke with three to six internal links usually reads naturally. A post crammed with links distracts readers and makes each link less useful.
Breadcrumbs and categories
Site structure supports the links. Putting a whole cluster in one category gives it a shared archive page, and breadcrumbs show readers where they are in the hierarchy. Google’s documentation on breadcrumb structured data explains how breadcrumbs can appear in search results, and most SEO plugins for WordPress can generate them automatically.
Publishing Order and Pace
Publish the pillar first. Spokes can then link to it from day one, and the pillar can be updated with a link to each spoke as it goes live. Publishing spokes before the pillar means going back to add links later, which is easy to forget.
A steady pace helps more than a burst. Spreading spokes over days or weeks gives time to check that each one is linked properly and to make sure the next spoke is not overlapping a post already live. After each spoke publishes, open the pillar and add the new link to the related guides list. That single habit keeps the cluster complete.
Avoid planning two pillars for the same day. A pillar is the biggest, most important page in its cluster, and giving each one room to be finished, checked and linked properly is worth the wait.
A simple tracking sheet
A spreadsheet keeps the plan visible. Useful columns include the cluster name, role (pillar or spoke), title, target keyword, intent, status, publish date, URL and whether the pillar has been updated to link to it. A glance at the sheet shows which spokes are missing and which links still need to be added.
Folding Old Posts Into a Cluster
Most established blogs already have posts that fit under a new pillar. Rather than starting over, map them in.
- Pull a list of every published post with its title, URL and word count.
- Tag each one with the pillar it fits under, or “none.”
- Look for overlaps. If two old posts answer the same question, consider merging them into one stronger post and redirecting the weaker URL to it.
- Add a link from each mapped post to its pillar and to one sibling.
- Add each mapped post to the pillar’s related guides list.
- Note gaps where no post answers an important question; those become new spokes.
Old posts with thin or outdated content may need a refresh before they earn a place in a cluster. A content audit, where every post is reviewed and marked to keep, update, merge or remove, is the systematic way to handle that.
Our Amazon Influencer program guide is an example of a pillar that pulled several older posts into its related guides list alongside new spokes.
Measuring Whether a Cluster Is Working
A cluster is a long-term project, so judge it over months rather than days. Google Search Console, the free tool Google provides for site owners, shows how each page performs in search: the queries it appears for, impressions, clicks and average position.
Checks worth making every month or two:
- Whether new spokes are indexed, using the Pages report or the URL Inspection tool
- Which queries each spoke appears for, and whether two spokes show up for the same query, a sign they may overlap
- Whether the pillar starts to appear for broader queries as more spokes link to it
- Which spokes earn clicks and which earn impressions without clicks, since a weak title or description may be the problem
Search Console’s own documentation notes that average position and impressions can shift for many reasons, including changes in how often a query is searched. Compare longer periods, such as three months against the previous three, rather than reacting to a single week.
Engagement data from an analytics tool adds the reader’s side. Pages that people leave quickly may not match the intent behind the query, which is a cue to revisit the format.
Common Mistakes
A few problems come up again and again when bloggers first build clusters:
- A pillar that is really just a long spoke, covering one narrow question instead of the whole topic
- Spokes that repeat each other with slightly different titles
- Spokes that never link back to the pillar
- A pillar that is never updated as new spokes publish
- Links to scheduled posts that are not live yet, which lead readers to errors
- Clusters built around topics with no connection to the site’s audience or income
Each of these is easy to avoid with a written plan and a tracking sheet.
Frequently Asked Questions
How many spoke posts should a topic cluster have?
There is no fixed number. Many bloggers plan 8 to 12 spokes per pillar to start, then add more as new questions appear. Every spoke should answer a distinct question.
How long should a pillar page be?
Long enough to cover every major part of the topic at a high level. That often means 3,000 words or more, but completeness matters more than word count.
Should spokes link to each other?
Yes, when they are closely related and the link helps the reader. One or two sibling links per spoke is usually plenty.
Do topic clusters help with Google rankings?
Google has not named clusters as a ranking factor. Its documentation does say links help it find pages and understand context, and a well-organized site with descriptive links is easier for both people and search engines to use.
Can I turn an existing post into a pillar page?
Yes, if it already covers a broad topic. Expand it to cover each major subtopic, add a related guides section, and link it to the spokes that fit underneath.Sources: Google Search Central, SEO Starter Guide; Google Search Central, Link best practices for Google; Google Search Central, Breadcrumb structured data; Google Search Central, Creating helpful, reliable, people-first content.