Topic cluster or semantic silo: what's the difference?

In short: The topic cluster organises content around a broad page covering a subject, along with satellite content linked to it—a method popularised by HubSpot from 2017 onwards. The semantic silo, theorised by Laurent Bourrelly in 2012–2013, instead structures content in hierarchical layers around a central intent, with an internal linking that is denser and more prescriptive.

Topic cluster and semantic silo: two answers to the same organisational need

Confusing the two is a bit like confusing a library organised by theme with one organised by reading path: both arrange the same content, but according to a different logic. The topic cluster addresses a need for quick editorial structuring around a broad subject. The semantic silo addresses a need for finer progression between several levels of intent.

This article objectively compares the two architectures based on their respective reference sources, without designating a universal winner.

The topic cluster, popularised by HubSpot

A topic cluster brings together a broad page covering an entire subject and several more targeted pieces of content addressing sub-topics, specific questions or particular use cases. Each of these pieces links back to the central content via a descriptive link, and links between them can be added when it serves the reader, though this isn't a requirement. This definition isn't a standard imposed by Google: it corresponds to a methodological proposal from HubSpot, popularised from 2017 onwards and now a reference point on the other side of the Atlantic.

The semantic silo, theorised by Laurent Bourrelly

The semantic silo is a French SEO architecture method associated with Laurent Bourrelly, who claims to have coined the term and theorised the concept between 2012 and 2013. According to a specialist glossary, the method organises content around a central subject broken down into thematic layers, with dense, hierarchical internal linking intended to strengthen the overall semantic coherence. The concrete details—number of layers, precise linking rules—can vary from one practitioner to another: this description comes from a popularising source, not a single, fixed protocol.

Please note

Neither the topic cluster nor the semantic silo is an official Google classification. They are two distinct methodological proposals—one popularised by HubSpot, the other by Laurent Bourrelly—that SEO professionals use to organise their content.

The criteria for objectively comparing the two methods

Comparing these two architectures requires setting common criteria, otherwise the comparison quickly becomes a matter of opinion. The criteria used here cover the origin and authorship of the concept, the unit of content organisation, the logic and density of internal linking, the degree to which the structure is prescribed, and the recommended context of use.

• Origin and authorship of the concept

• Unit of content organisation (broad page and satellites, or hierarchical layers)

• Logic and density of internal linking

• Degree to which the structure is prescribed

• Recommended context of use

This framework is an analytical comparison between two reference descriptions, not an official classification imposed by a search engine. Where a point remains unclear in a source—for example, the exact implementation details of the semantic silo—it is flagged as variable depending on the practitioner, rather than filled in with a detail borrowed from the other model.

Comparison table: topic cluster vs semantic silo

The table below applies the same five criteria to both methods. Each cell reflects only what the corresponding reference source confirms.

In everyday SEO vocabulary, the two terms are often used interchangeably, given the lack of uniform terminology in the market: both methods rely on central content, related content and internal linking, which explains this frequent overlap.

Criterion-by-criterion comparison: what truly sets the two architectures apart

Two criteria account for most of the difference: the unit of organisation chosen, and the way internal links flow through the structure.

Unit of organisation: pillar and satellites, or hierarchical layers?

The most useful distinction concerns the methodological emphasis of each approach. The topic cluster starts from a broad page and standalone satellite content, each capable of being read independently. The semantic silo more strongly formalises a layered structure, designed to guide the reader from a broad intent towards a more specific one.

Internal linking: simple attachment or hierarchical circulation?

The topic cluster mainly requires an explicit relationship between each satellite piece of content and the central content: this is the method's minimum requirement. The semantic silo places greater emphasis on hierarchical, contextual link circulation within the structure, including between pages at the same level, depending on the chosen implementation. Both methods therefore rely on internal links; what changes is the degree of prescription expected in their arrangement, not their existence.

Why the two concepts are often confused

Both models rely on the same basic ingredients: central content, related content, and internal linking that connects them. Without uniform terminology across market sources, this kinship explains why the two terms are frequently conflated, or even used as synonyms in professional discussions. It's better to explicitly define the chosen model at the start of a project than to assume total equivalence between the two approaches.

Advantages and limitations of each architecture

Strengths and limitations of the topic cluster

The topic cluster enables quick editorial structuring around a broad theme, with a simple, explicit relationship between each satellite piece of content and the central content: this is its main strength. Its limitation lies in the fact that it says little about how links should flow between the satellite pieces of content themselves. If the subject requires fine progression between several levels of intent, this may call for additional contextualisation work that the method, as described by HubSpot, doesn't detail.

Strengths and limitations of the semantic silo

The semantic silo offers a layered structure designed to guide the reader between different levels of intent, with dense, hierarchical internal linking intended to ensure overall semantic coherence. Its limitation lies in a more demanding formalisation, with implementation details that vary from one practitioner to another, given the lack of a standard recognised by Google. For professionals who want to go further with this specific approach, the complete method for implementing a semantic silo in SEO details the concrete steps for building such a structure.

Key takeaway

The topic cluster favours simplicity and speed of implementation; the semantic silo favours precision in the progression between intents, at the cost of more demanding formalisation. Neither limitation is a dealbreaker: they simply guide the choice depending on the project.

Which architecture should you choose based on your project's profile?

The topic cluster is suitable when you need to quickly deploy or clarify an editorial strategy around a broad theme. The semantic silo is better suited when the project justifies precisely designing levels of intent, reading paths and link relationships between pages.

This choice doesn't remove the need for intent research, the production of genuinely useful content, or a technical audit of the site: no architecture, whichever one you choose, will make up for these gaps.

In practice, a site wanting to quickly cover a theme with several sub-topics will tend to choose a topic cluster. A site wanting to build a highly guided reading path across several levels of need, from the most general to the most specific, will tend to choose a semantic silo.

Implementing either method: the same groundwork

Whichever label is chosen, solid implementation starts with the same steps.

1. Precisely define the central subject

2. Identify the sub-intents and the content needed to address them

3. Assign a non-cannibalising role to each page, to avoid two pieces of content addressing the same intent

4. Create contextual, explorable internal links between these pages

This last step requires that each page remain accessible to Google via standard HTML links, with a href attribute filled in, and that each link genuinely helps the reader delve deeper into the subject rather than serving ranking purposes alone.

Do these architectures genuinely improve SEO in 2026?

Neither the topic cluster nor the semantic silo is presented by Google as a standalone ranking system. Its recommendations focus on crawlable, contextual internal links, along with useful, original content designed first and foremost for users.

A content architecture, however carefully crafted, never compensates for a lack of editorial value, uncrawlable pages or duplicate content.

Since May 2026, Google confirms that these fundamentals, crawlable content, a clear technical structure, reduced duplication, remain applicable to its generative search features. This guarantees neither indexing nor display within a generative feature: it merely confirms that technical and editorial basics retain their relevance.

The priority remains useful depth and originality of content, rather than the mechanical multiplication of pages around a topic.

Point to watch

Stacking satellite pages or thematic layers without genuinely useful content produces no ranking benefit whatsoever. Architecture organises what already exists; it never replaces the editorial value of each individual page.

Conclusion: two methods, no universal winner

The choice between the two methods depends on the profile of the project and the level of architectural granularity sought, not on any inherent superiority of one over the other. A broad theme to be covered quickly points towards a topic cluster; a precise reading journey across several levels of intent points towards a semantic silo.

Before applying a label, it's best to check concretely, for your own site, the exact role of each page and the real coherence of your internal linking: it is this verification, more than the name given to the method, that determines the overall solidity.