Siloing is a way of organising a website so that pages on the same topic are grouped together, both in the URL structure and in how they link to each other, with each group sitting under a main page for that topic. The aim is to make every subject area clear to visitors and search engines.
How siloing works
There are two parts. A physical silo uses folders in the URL: an electrician’s site might have /domestic/ with /domestic/rewiring/ and /domestic/eicr/ beneath it, and /commercial/ with its own pages. A virtual silo uses internal links: pages within a group link to each other and to the group’s main page, while links between groups are made deliberately.
The main page of each group, often called a hub or pillar page, introduces the subject and links down to the detailed pages. Those pages link back up and across to close siblings, and breadcrumbs reinforce the hierarchy. The result is a clear site architecture in which every subject has a home.
Siloing began as a strict discipline in which pages in one silo should never link into another. Most practitioners now take a softer view, close to the topic cluster model: group content tightly, but link across groups wherever it genuinely helps the reader.
Why it matters
Grouping content by topic helps search engines see what a site covers and which page matters most for each subject. Internal links pass authority, so a hub that receives links from every page in its group is strengthened, and new pages added to the group are found and understood quickly. It also builds topical authority, because depth across a subject is visible rather than scattered across unrelated posts.
For visitors, a clean structure means they can find related information without hunting, and each section becomes a natural path from general to specific. For a UK accountancy practice, a Self Assessment section with pages on deadlines, allowable expenses and late filing penalties, all linked to the Self Assessment service page, is easier to use and easier to rank than the same articles scattered through a blog.
Common mistakes
- Enforcing rigid silos that forbid useful links, such as a heating page refusing to link to a related plumbing page the customer clearly needs.
- Building deep folder paths (/services/home/heating/boilers/combi/) that add length without adding clarity.
- Creating silos around internal departments rather than around how customers think and search.
- Silos holding one or two thin pages, which add structure but no depth.
- Changing the folder structure of an established site without redirects, losing the signals built up on the old URLs.
- Blog posts left outside every group, with no links to the relevant hub or service page.
How to act on it
List your main subjects, based on what you sell and how customers search, and give each one a hub page. Assign every other page to one hub, then look for gaps (topics with no supporting content) and overlaps (two pages answering the same question). Keep URLs short; for a small or medium site, one level of folder is usually enough.
Next, link each supporting page to its hub with a descriptive anchor, link related pages within the group, and add cross-links only where the reader would benefit. On an existing site this is often best done through links first, leaving URLs alone, because changing URLs means redirects and a period of disruption. Planning topic groups and how they connect is part of my content SEO and strategy service.