A topic cluster is a group of pages that cover one subject from different angles and link to each other, usually around one broad page that ties them together.
The idea is right, and it’s how most sites that rank well are organized whether they call it a cluster or not.
What goes wrong is the formula most guides turn it into.
Write a pillar page, write twenty posts around it, link everything to everything, and wait for “topical authority” to kick in.
That’s how you end up with twenty thin posts competing with each other and a pillar page nobody links to. What a cluster actually needs is one page per real question, sensible links between them, and a topic that leads to something you sell.
The short version
- A topic cluster is one broad pillar page plus several pages on specific subtopics, all linked together.
- Topical authority isn’t a score Google gives you. It’s shorthand for a site covering a subject so thoroughly that it gets trusted to rank for more of it.
- Pick cluster topics you can realistically compete on and that lead to something you sell or want.
- Plan the cluster from real searches, one page per search intent. If two keywords show the same results in Google, they belong on one page.
- The pillar can be a guide, a category page or a service page. It depends on what you want that page to rank for.
- Link every cluster page to the pillar, the pillar to every cluster page, and related cluster pages to each other.
- Measure the cluster as a group in Search Console, and give it a couple of months.
What a topic cluster is
A topic cluster has three parts. The pillar page covers a broad topic at a high level, the cluster pages each go deep on one subtopic, and internal links connect them so both readers and Google can move between them.
Take a plumber in one city. The pillar might be the “Water Heater Services” page. The cluster pages would answer the specific questions people search for before they call someone, like how long a water heater lasts, tank versus tankless, why the water smells like rotten eggs and what a replacement costs.
Each of those pages links back to the service page, and the service page links out to each of them.
You’ll also hear this called hub and spoke, content clusters, or a pillar content strategy. They’re all the same idea with different names. HubSpot popularized the model years ago with a post calling topic clusters “the next evolution of SEO,” and the name stuck.
What topical authority really means
Topical authority is one of those SEO terms that sounds like a metric but it’s not exactly like that.
There’s no topical authority score in SEO and Google has never said it measures one for regular websites.
What Google does have is a system called topic authority, announced in 2023, but it’s specifically for news.
It helps Google surface publications with real expertise in an area, like a local paper covering a disaster in its own town, based on things like how notable a source is for a topic or location and its history of original reporting.
For everything else, the best hint we have comes from the Google documents that leaked in 2024. Mike King’s analysis of them points to two attributes, siteFocusScore and siteRadius, which compare each page to the site as a whole to see how closely the site sticks to one topic and how far a page strays from it.
What we don’t know is how much weight those carry in rankings.
In practice, a site that covers a subject thoroughly and consistently tends to rank for more of that subject over time, and new pages on that subject tend to rank faster.
A site that publishes about everything tends to struggle with all of it. Topic clusters are simply the most organized way to be the first kind of site.
Pick a topic you can win and that leads somewhere
The most common mistake with topic clusters happens before a single page gets written, and it’s picking the wrong topic.
A cluster is a big investment, often ten or more pages, so the topic has to pass two checks.
The first check is whether you can realistically compete.
If every result for the broad topic is a huge brand with thousands of linking sites, start with a narrower angle where smaller sites still rank, and widen it later.
My guide on types of keywords covers how to spot the specific, lower-competition searches that make good cluster pages.
The second check is whether the traffic leads anywhere. A cluster about a topic your customers never search for can rank beautifully and do nothing for the business.
The best clusters sit one step before the thing you sell. The plumber’s water heater cluster works because someone reading about tank versus tankless is close to hiring someone.
Map the cluster from real searches
Once you have the topic, list every search people make around it. Start with keyword research, then add the questions from Google’s People Also Ask boxes, your own Search Console queries and the questions customers ask you directly.
Then group the list by search intent, not by keyword. This is where a lot of cluster plans go wrong, because keyword tools happily suggest twenty variations that are really the same question asked twenty ways.
The test is simple. Search two keywords that look similar. If Google shows mostly the same pages for both, they belong on one page.
If the results are different, Google sees them as different questions, and each one can have its own page. Many keyword tools with a clustering feature group keywords this way automatically, by comparing how many of the same pages rank for each one.
It also helps to know that one page can rank for a lot more than one keyword. The average top-ranking page also ranks in the top 10 for nearly 1,000 other keywords, so a single well-built page picks up the variations on its own.
So resist the urge to create a page for every variation. Google’s own AI search guide warns that creating separate content for every variation of how people might search, mainly to manipulate rankings, violates its scaled content abuse policy, and calls it an ineffective long-term strategy. Splitting one topic into many thin pages also creates keyword cannibalization, where your own pages compete with each other and none of them ranks well.
A typical cluster ends up with somewhere between five and fifteen cluster pages. That’s not a rule though, just what tends to happen when you group by intent properly.
Decide what the pillar is
The pillar page is the page that targets the broadest search in the cluster, and it doesn’t have to be a long blog post. What it should be depends on what that broad search wants.
If the broad search is informational, like “WordPress SEO,” the pillar is a complete guide that covers every subtopic briefly and links to the cluster page for each one.
If it’s commercial, like “water heater repair Pasadena,” the pillar is your service page, and the informational cluster pages feed readers and links into it.
On an online store, the pillar is often a product category page, with buying guides and comparisons as the cluster.
Length isn’t a goal either, by the way. A good pillar page is as long as it needs to be to give a real overview and point people to the right detail page, and a 6,000-word pillar that repeats everything in its cluster pages is just a cluster page competing with its own spokes.
Give each subtopic a short section that answers the basic question, and link to the cluster page for everything beyond that.
Link the cluster together
The links are what turn a pile of related posts into a cluster. Every cluster page should link to the pillar, the pillar should link to every cluster page, and cluster pages should link to each other where it actually helps the reader, like a post on water heater lifespan linking to the one on replacement cost.
Two rules from my internal linking guide matter most here. Give the pillar one main anchor text and use it (or close variations) whenever you link to it, and never use the same anchor for two different pages.
Then link to the cluster from outside it too. Your homepage, your menu and your best-linked posts should point at the pillar, because that’s how the authority your site earns reaches the cluster.
Google’s own advice is that every page you care about should have a link from at least one other page on your site. In a cluster, every page should have several.
Topic clusters on WordPress
WordPress gives you most of what you need for clusters out of the box, but a few decisions are worth making on purpose.
Categories are the natural way to group a cluster. Put every cluster page in the same category, and either use the category archive itself as the pillar or keep the category as a simple list and build the pillar as a separate page.
If you use the archive as the pillar, give it a real introduction with links (most themes and SEO plugins let you add one to the category description), because an archive that’s only a list of post titles makes a weak pillar.
Keep the category out of your URLs. A permalink structure like /category/post-name/ means that moving a post to a different cluster changes its URL, and every change like that needs a redirect.
A simple /post-name/ structure lets you reorganize clusters freely, and the category and breadcrumbs show the structure instead.
Related posts plugins help, but they don’t replace links in the body of the post. They pick “related” posts by their own logic, often by tags or recency, and they don’t know which page is your pillar. Add the important cluster links by hand in the text, and let the plugin handle the extras.
A real cluster, from this site
The biggest cluster I’m building on this site is around WordPress SEO. It looks like this.
| Page | Role | Status |
| WordPress SEO, the complete guide | Pillar | Planned |
| On-page SEO checklist | Cluster | Live |
| Internal linking guide | Cluster | Live |
| Local SEO on WordPress | Cluster | Live |
| Technical SEO checklist | Cluster | In progress |
| Best SEO plugins for WordPress | Cluster | Planned |
| WooCommerce SEO guide | Cluster | Planned |
| WordPress speed optimization | Cluster | Planned |
| Migration and redesign SEO checklist | Cluster | Planned |
| 301 redirects in WordPress | Cluster | Planned |
Every page targets a different search intent, so none of them should compete with another. Rank Math vs Yoast, for example, sits under the plugins page as its own smaller branch, because “which SEO plugin” and “Rank Math or Yoast” are different questions.
And the pillar will be a guide rather than a service page, because “WordPress SEO” is an informational search, while the service pages on this site sit on their own.
How to tell if a cluster is working
Measure the cluster as a group, not page by page.
In Search Console’s Performance report, filter pages with a regex that matches every URL in the cluster (a list like on-page-seo|internal-linking|technical-seo works), and watch impressions, clicks and the number of queries the group ranks for. If you use a tool like SEO Gets, you can save the cluster as a group and track it the same way.
The signs of a cluster that’s working are the group’s impressions and query count growing month over month, new cluster pages starting to rank faster than older ones did, and the pillar picking up rankings for broader terms.
If individual pages are stuck, check that they’re linked properly and that two pages aren’t competing for the same queries before you write anything new.
Give it time. A cluster usually takes several months to show its full effect, because Google needs to crawl and index the new pages, and the pillar needs time to build up its authority through the links pointing to it.
Mistakes that break topic clusters
Most cluster failures come from the same few mistakes, so check for these before adding more content.
Thin cluster pages are the most common. If a cluster page could be a paragraph on the pillar, it should be one. Pages that exist only to hit a keyword variation dilute the cluster and compete with the pages that matter.
Orphaned pillars are next. Plenty of sites build a great pillar and then link to it only from its own cluster, so it never gets the authority it needs to rank for the broad term. Link to it from the menu, the homepage and your strongest posts.
Clusters with no business value are the quiet one. They rank, bring traffic and never lead anywhere, and they take the same effort as a cluster that would have.
And skip Google stacking.
That’s the tactic of building a network of interlinked Google Docs, Sheets, Sites and Drive folders pointing at your site to build “entity authority.”
I haven’t seen convincing evidence that it does anything measurable, and it’s a manufactured link scheme with Google branding on it, which puts it firmly in the grey area I cover in my guide to white, grey and black hat SEO.
The time is better spent on one more real cluster page.
If you want more practical guides like this one, Built to Rank is my occasional newsletter on what’s actually working in SEO. It only goes out when I have something worth sending.
A couple more questions
How many articles should a topic cluster have?
As many as there are distinct search intents in the topic, which usually works out to somewhere between five and fifteen. Start with the pages closest to what you sell and add the rest over time.
How long should a pillar page be?
Long enough to give a real overview of every subtopic and link to the detail pages, and no longer. Word count isn’t the goal, and a pillar that repeats its cluster pages ends up competing with them.
What’s the difference between a topic cluster and a topical map?
A topical map is the plan for a whole site, listing every topic and subtopic you want to cover. A topic cluster is one section of that map, built around a single pillar. Most sites need a handful of clusters, and the topical map is just the list of them.
Do topic clusters still matter with AI search?
Yes. Google says its AI Overviews and AI Mode rely on its core ranking systems and pull related pages through several searches at once, so a site that covers a topic properly, with pages that each answer a specific question, has more chances to be one of the sources. What doesn’t work is splitting a topic into a page for every possible variation, which Google explicitly warns against.