Content Silo vs Topic Cluster: Which Should You Build?

Content silo vs topic cluster is a choice between two ways of grouping related pages. A content silo is a strict structure: pages on one theme sit together, often in one URL folder, and they link mostly inside their own group. A topic cluster is a looser hub model: one broad pillar page links to narrower cluster pages, and each cluster page links back. My verdict: build topic clusters for most sites, and add silo-style folders only when your site is big enough for them to help.

That’s the quick answer. The details matter, because the wrong pick can lock you into URLs you’ll regret, or into a linking rule that blocks the most useful links on your site.

Why This Choice Is Harder to Undo Than It Looks

Content is easy to edit. Structure isn’t. Once hundreds of pages sit in folders and other sites link to those URLs, a restructure means redirects, lost signals during the move and a lot of checking.

So I treat this as a decision you make once, early, and carefully. Two mistakes come up again and again in audits. Small sites copy a rigid silo diagram and end up with deep, folder-heavy URLs for a handful of pages. Blogs call a tag archive a “cluster.” Neither is the model working as designed.

What Is a Content Silo?

The silo idea comes from Bruce Clay, Inc., a US SEO agency that describes itself on its own siloing guide as the original inventor of siloing. Their method groups pages by theme, going from a broad landing page down to more specific supporting pages, so a site mirrors how people search.

Bruce Clay describes two versions:

• Physical (directory) silos. Related pages live in the same URL folder, like /peanut-butter/creamy/. The folder structure itself groups the theme.
• Virtual silos. The grouping comes from internal links, not folders. Every supporting page links up to the silo’s landing page and across to the other pages in that same silo.

Their guide calls virtual siloing essential and physical siloing a helpful extra that isn’t always feasible. That’s a detail most summaries skip.

The strict part is the cross-linking rule. Bruce Clay’s guide says linking from a supporting page in one silo to a supporting page in another silo dilutes both themes. If you must link across, it suggests linking to the other silo’s landing page instead, or using rel="nofollow" on the link. That rule is what makes a silo a silo.

What Is a Topic Cluster?

The topic cluster model is most closely tied to HubSpot. HubSpot’s own blog post on topic clusters traces the model to its 2015 “Topics Over Keywords” research by Anum Hussain and Cambria Davies, and HubSpot pushed the pillar and cluster setup into the mainstream from there.

The setup is simple:

1. A pillar page covers a broad subject at a high level.
2. Cluster pages each answer one narrower subtopic, question or use case.
3. Links run both ways. Every cluster page links to the pillar, and the pillar links out to each cluster page.

Notice what’s missing. There’s no rule about URL folders, and there’s no ban on linking between clusters. A cluster page about keyword difficulty can link to a page in a different cluster about backlinks if the reader needs it. The model is about making relationships clear, not about sealing groups off from each other.

Pillar page design is its own topic, and I won’t go deep on it here.

Content Silo vs Topic Cluster: Where They Actually Disagree

People often say silos and clusters are “basically the same thing.” They overlap a lot. Both group related pages. Both use a hub page. Both rely on internal links. But they split on three points that change how you build the site.

The biggest split is the linking rule. A silo treats cross-links as leaks. A cluster treats them as normal. Which view fits how Google works today? That’s the next question.

What Has Google Said About Site Structure and Internal Links?

Google hasn’t endorsed either model by name. What it has published is general guidance, and I think it points clearly in one direction.

Start with folders. Google’s SEO Starter Guide says that if your site has more than a few thousand URLs, how you organize content can affect crawling and indexing. It adds that grouping similar topics in directories can help Google learn how often URLs in each directory change. The same guide says keywords in the domain name or URL path alone have hardly any effect beyond appearing in breadcrumbs.

Read that carefully. Folders are a crawl-management tool for large sites, not a ranking trick. For a 60-page service business, a physical silo mostly gives you longer URLs. My post on URL structure for SEO covers folders versus flat URLs in more detail.

Now links. Google’s link best practices say every page you care about should have a link from at least one other page on your site. They ask you to think about what other resources on your site could help a reader understand a page, and to link to them in context with descriptive anchor text. Google also says there’s no ideal number of links on a page.

Nothing in that guidance says “only link within your theme.” It says link where it helps the reader.

Then there’s nofollow. In September 2019, Google announced on its Search Central blog that nofollow, sponsored and ugc are all treated as hints about which links to consider or exclude, not strict commands. My reasoning follows from that: putting nofollow on your own internal links to “protect” a silo is an old PageRank-sculpting habit. It doesn’t reliably control anything, and it tells Google you don’t vouch for your own page. I don’t use it on internal links, ever.

Four Questions That Settle It for Your Site

When I audit a site’s structure, these are the four questions I ask first. Answer them and the choice mostly makes itself.

1. How many URLs will the site have in two years? Under a few thousand, folders are optional and I lean cluster. Well above that, like a large store or publisher, folders start to earn their place for crawl management.
2. Do your topics overlap? If your subjects share questions, strict silos will block useful links. SEO topics overlap constantly, for example. A dentist’s services overlap far less.
3. Are your URLs already live and linked? If yes, don’t restructure folders just to match a diagram. Change the internal links instead.
4. Does your CMS force a structure? Shopify fixes some paths, like /collections/ and /products/. WordPress lets you choose. The platform can make the decision for you.

My Verdict: Clusters for Linking, Folders Only When They Earn It

A topic cluster is the better choice for most small and mid-sized sites because it matches Google’s documented link advice and costs little to change later. However, if you run a large site with thousands of URLs in clearly separate sections, silo-style folders are worth adding for crawl management, with cluster-style linking inside and across them.

In plain terms: take the useful half of each model. From silos, keep the idea of planning themes before you build and, on big sites, grouping sections in folders. From clusters, keep the two-way links between pillar and cluster pages and the freedom to link across topics when a reader needs it.

What I’d drop completely is the no-cross-linking rule and any internal nofollow. Those come from an era when SEOs tried to steer PageRank inside a site by hand. Honestly, I don’t see a case for them on a site built for readers today.

If you want the groups themselves built from real search data, not guesses, that’s part of our keyword research service, and topical maps are included.

When Would I Still Build a Strict Silo?

A qualified verdict needs real exceptions. These are the situations where I’d lean silo, or at least keep a group more sealed off than usual.

• Big ecommerce catalogs. A store with thousands of products in distinct departments gets real value from department folders. Crawl patterns differ between a fast-changing sale section and a stable guide section, which is exactly the case Google describes.
• Sites serving very different audiences. A company with a consumer section and a separate B2B section may want each area self-contained, so readers don’t wander into content meant for someone else.
• Multi-location or multi-brand sites. When each location or brand needs its own clean area, a folder per location keeps things tidy for users and for reporting.
• Reporting needs. Folders make Search Console filtering easy. If your team reports by section, that’s a practical reason to use them, even if it isn’t a ranking reason.

Even in these cases, I keep cross-links where they help the reader. A silo folder is fine. A silo wall usually isn’t.

Can You Combine Silos and Topic Clusters?

Yes, and on larger sites, that’s what I usually build. The folder handles the big grouping. The cluster handles the linking.

Picture a site with three service lines. Each line gets its own section, maybe its own folder. Inside each section, a pillar page links to its cluster pages and they link back. And when a page in one section genuinely answers a question raised in another, it links there directly, with a descriptive anchor and no nofollow.

The planning step comes first. A topical map tells you which subjects belong together and which page owns each one. My guide on how to create a topical map walks through building one, and keyword mapping covers assigning exactly one owner page per keyword so two pages in the same group don’t compete.

How do you know which queries belong in the same group? Shared words can mislead you. I’d check whether Google shows overlapping results for them, which is what SERP based keyword clustering does.

How Should You Move a Siloed Site Toward Clusters?

If your site already uses strict silos, you don’t need to tear it down. Most of the fix is internal links, and links can change without touching a single URL.

Here’s the order I’d follow:

1. Keep existing URLs. Don’t move pages between folders unless there’s a clear business reason. If you must, 301 redirect every old URL.
2. Remove internal nofollow. Audit internal links for rel="nofollow" and take it off links between your own pages.
3. Add the missing cross-links. Look for pages that answer a question raised on a page in another silo, and link them in context.
4. Check each pillar. Make sure every group has one page that summarizes the subject and links to every cluster page.
5. Find orphan pages. Every page you care about should have at least one internal link pointing at it, as Google’s guidance says.

A site crawler such as Screaming Frog SEO Spider will list internal nofollow links. To spot orphans, compare the crawl against your XML sitemap or Search Console pages. Then watch Search Console for a few weeks after the changes.

This kind of structure work also feeds the bigger goal of covering a subject well, which I explain in topical authority vs domain authority, and if your site is only a few months old, my plan for building topical authority on a new website covers the publishing order. Not sure whether your current structure is holding you back? A free SEO audit is a quick way to find out.

Frequently Asked Questions

Is Silo Structure Still Good for SEO?

Parts of it are. Planning themes before you build and grouping large sections in folders still help, especially on big sites. The strict rule against linking between silos, and using nofollow on internal links, don’t match Google’s current link guidance, so I’d drop those parts.

Should Links Between Silos Be Nofollow?

No. Google has treated nofollow as a hint since 2019, so it doesn’t reliably control how link value flows, and it signals that you don’t vouch for your own page. If a page in another section helps the reader, link to it normally with descriptive anchor text.

Is a Topic Cluster the Same as a Hub and Spoke Model?

They’re close enough that most people use the terms as synonyms. Both describe one central page linked to several narrower pages that link back. “Topic cluster” and “pillar page” are the terms HubSpot popularized, while “hub and spoke” is a more general description of the same shape.

Do Topic Clusters Need Their Own URL Folder?

No. The topic cluster model has no folder rule, and the links do the grouping. Add folders when your site is large enough that crawl management or section-level reporting makes them useful.

Last updated: September 2026 by Mizanur Rahman