Publishing content without a plan leaves you with a pile of disconnected pages. Google can’t read them as proof of expertise. Neither can ChatGPT or AI Overviews.
Semrush’s updated guide to topic clusters makes the case plainly: ranking algorithms and AI answer engines both reward sites that can demonstrate topical depth. Clusters are how you demonstrate it on purpose instead of by accident.
What a topic cluster actually is
A topic cluster is a group of thematically related pages on your site, tied together by internal links.
One pillar page gives the broad overview of the core topic. Multiple cluster pages (subpages) go deep on individual subtopics. Every page links to the pillar; the pillar links back out to every page.
Semrush points to restaurant scheduling platform 7Shifts as an example: its guide to restaurant costs acts as the pillar, linking out to pieces on restaurant bookkeeping, accounting and labor costs.
Why this matters more in the AI era
Here’s the shift performance and content teams should care about. AI search platforms use query fan-out \u2014 they take one user question, expand it into several related sub-queries, then compose an answer from what they find.
A well-built cluster naturally answers those sub-queries. Each subpage becomes a clean, authoritative destination for one slice of the topic, which increases your odds of being cited rather than skipped.
Semrush also flags the cannibalisation problem: when two of your pages chase the same terms, search systems have to guess which one to surface. Mapping one keyword cluster to one page removes that guesswork.
The five-step build
- Choose a core topic. Broad enough for several pieces of content, narrow enough to stay focused. Look at what your audience cares about, what’s already worked, and what competitors cover.
- Research keywords. Filter for suitable intent \u2014 informational, commercial, transactional \u2014 and a difficulty score you can realistically compete on.
- Identify pillar and subpages. The pillar should target the broad head term, be the most complete resource on the topic, and map its H2s and H3s to the subtopics your subpages cover.
- Create the content. Start with the pillar. Structure it around the subtopics you’ll cover separately so linking out is easy as you publish. Then add cluster pages at your own pace.
- Measure it as a unit. Not just page by page.
The metrics that tell you if it’s working
Semrush narrows cluster health down to a few signals worth watching:
- Organic traffic to the pillar page versus its subpages
- How often visitors click from one cluster page to another
- How much of the cluster’s target keyword set you actually rank for
- Whether the cluster shows up in AI-generated answers, not just Google results
Together these tell you whether you’ve built a connected structure or just a handful of pages that happen to share a theme.
Three clusters already doing the job
Healthline uses “Everything You Need to Know About Allergies” as a pillar covering symptoms, causes and treatments \u2014 with each subtopic getting its own dedicated subpage.
Petcube runs a “Puppy Care 101” guide as its pillar, linking out to deeper guides on raising a puppy, adopting from a shelter, puppy-proofing, supplies and crate training.
Wistia takes a different structural approach: its video marketing guide is built as sequential chapters rather than a flat overview \u2014 a format that works when subtopics build on each other. It also embeds instructional videos, making the pillar valuable on its own.
What to do this quarter
If you’re starting a new site or a new content line, don’t spread thin. AI SEO practitioner Nathan Gotch has recommended that new sites prioritise building authority around a single topic or service line for the best results.
Pick one topic. Ship the pillar. Then add subpages steadily and link them both ways with keyword-rich anchor text.
And treat the cluster as living infrastructure, not a campaign. Keep the pillar evergreen as the topic evolves. Add new subpages when fresh subtopics earn a place. That’s the difference between a content archive and an authority asset.
Source: Semrush Blog
