ONPAGE · SEO GLOSSARY
Silo Structure
A content organisation approach that groups thematically related pages into isolated sections with strong internal linking within each silo — building topical authority within each theme and preventing dilution from cross-topic linking.
Definition
A silo structure in SEO organises website content into distinct topical sections (silos), where pages within each silo are strongly interlinked, but cross-silo linking is minimised or controlled. The concept, associated with SEO practitioner Bruce Clay, is based on the idea that concentrated internal link flows within a topic area signal strong relevance to Google for that topic. Structure: (1) a top-level silo page (the pillar or category page) that covers a broad topic; (2) supporting pages covering specific subtopics, linked from the silo root and back to it; (3) minimal links between pages in different silos. The logic: if your plumbing pages all link to each other but don't link to your roofing pages, the plumbing cluster's PageRank circulates within the plumbing silo, reinforcing its topical relevance. A topic cluster model is the modern equivalent of a silo structure, with more flexible cross-topic linking rules.
Why it matters for SEO
Silo structure affects how PageRank and topical relevance flow through a site. A well-structured silo concentrates link equity and topical signals on the pages where they matter most — the pillar or category page can accrue more authority than if its link equity were diluted across the entire domain. The practical benefit: pillar pages in tight silos tend to rank better for competitive category-level queries. The risk: overly strict silos that prevent users from discovering related content can reduce engagement and make the site feel fragmented. Most modern SEO practitioners implement a looser version — strong within-topic internal linking with controlled cross-topic linking on contextually relevant anchor text.
How DeepSEOAnalysis checks this
The audit analyses the internal link graph: which pages receive the most internal links (likely silo roots or pillar pages), which pages are weakly connected (potential silo islands receiving no inbound links from the silo root), and whether orphan pages exist within what appears to be a content cluster. It surfaces the internal link depth distribution — pages buried 4+ clicks from the homepage often indicate a silo with poor internal linking from the root to leaf pages.
Useful tools and resources
GLOSSARY
Related terms
onpage
Topic Cluster
A content architecture model where a broad pillar page links to multiple cluster pages covering specific subtopics — building topical authority by demonstrating comprehensive coverage of a subject.
Read definition →links
Pillar Page
A comprehensive hub page on a broad topic that links to and receives links from cluster pages covering specific subtopics — the foundation of a content cluster strategy.
Read definition →links
Internal Linking
Links between pages on the same domain that distribute PageRank, establish site hierarchy, and guide crawlers to important content.
Read definition →links
Topical Authority
A site's perceived depth of expertise in a subject area, built by covering a topic comprehensively rather than by accumulating generic backlinks.
Read definition →technical
Crawl Depth
The number of clicks (links) a crawler must follow from the homepage to reach a given page — pages deeper than 4 clicks receive less frequent crawling and less internal PageRank.
Read definition →See how your site scores on Silo Structure.
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