Many sites publish posts as ideas come along, then connect them more or less at random through “related posts” widgets. A topic cluster tackles the problem from the other end: you start from the questions people ask about a subject, derive the page structure from them, and decide up front which links each page should carry. The approach is often compared to “siloing”. In French-speaking SEO, a stricter variant with tighter linking rules, the “semantic cocoon” (cocon sémantique), was popularized by Laurent Bourrelly.
How a topic cluster works
- The pillar page covers the broad topic and targets the most general query.
- Cluster pages each explore one subquestion. They link back to the pillar page and to a few closely related sibling pages.
- Supporting pages answer very specific questions, often long-tail ones, and link back up to their cluster page.
Links are placed in the body text, where they help the reader, with descriptive anchor text. A link to another cluster is still possible, but only when it makes real editorial sense. Each page should answer a single search intent, so that two pages in the same cluster don't compete for the same query.
What Google says about it
Google never talks about topic clusters or semantic cocoons, but its recommendations on links point in the same direction. Every important page should get a link from at least one other page on the site; internal links help visitors and search engines move through the content; good anchor text is descriptive, concise and relevant to both pages. Google also states that there is no ideal number of links per page. For large sites, its SEO starter guide notes that grouping pages on the same topic into directories can help it understand how often each section changes. Nothing, however, documents an effect specific to strict cluster rules: the benefit mostly comes from thorough content and consistent internal linking.
For WordPress
- WordPress pages accept a parent page, which reflects the hierarchy in the URL; for posts, one category per cluster plays a similar role.
- Links are added by hand in the block editor, within the text: that is what makes the difference with an automatic widget.
- Breadcrumbs remind readers where they are in the hierarchy.
On our blog, the 2026 WordPress security checklist acts as a pillar page: most of its items link to an article that covers them in detail, such as the one on limiting login attempts.
Common mistakes
- Creating pages just to fill the structure: a supporting page with no useful answer weakens the cluster instead of strengthening it.
- Piling links into the menu and footer: they connect everything to everything and blur the intended hierarchy.
- Forgetting maintenance: a post added later must be linked to its pillar and its siblings, otherwise it stays orphaned.