URL Hierarchy
A clean URL hierarchy is how Google reads your SILO structure at a glance. Learn the Hub → Pillar → Spoke pattern and the folder-depth rule.
What you'll learn
- Understand how URL structure reflects (and reinforces) topical hierarchy
- Learn the Hub → Pillar → Spoke URL pattern
- Know the folder-depth rule for important pages
- Recognize URL-structure mistakes that hurt topical authority
URLs Are a Map, Not Just an Address
A well-designed URL structure lets Google (and users) infer the site's topical hierarchy directly from the path. /mortgages/ is a hub. /mortgages/fixed-rate/ is a pillar within it. /mortgages/fixed-rate/best-lenders-uk/ is a spoke page beneath that pillar.
The Folder-Depth Rule
Important, SEO-priority pages should sit no deeper than 3 folder levels from the root. Every extra folder level dilutes internal link equity flowing to that page and makes it harder for Googlebot to discover through normal crawling. Screaming Frog's "Folder Depth" column, cross-checked with its Link Score, is the standard way to audit this.
| Pattern | Depth | Verdict |
|---|---|---|
| /car-loans/bad-credit/ | 2 | Good — pillar-level page, easy to reach |
| /car-loans/bad-credit/uk/london/ | 4 | Risky — too deep for a page meant to rank competitively |
| /blog/2023/03/15/post-title/ | 4 | Common CMS default — flatten to /blog/post-title/ where possible |
Matching URLs to SILO Boundaries
Pages within the same SILO should share the same URL prefix. Pages from different SILOs should never nest inside each other's folders — that signals to Google that the topics are related when they aren't, and it complicates internal linking rules (SILO pages should mostly link within their own SILO).
Common URL Mistakes
- Parameters (
?sort=price) used for core navigation instead of clean paths - Dates baked into URLs for evergreen content, making them look stale and forcing unnecessary depth
- Mixing category logic — the same subtopic appearing under two different parent folders
- Changing URL structure without 301 redirects, losing accumulated link equity
Key Takeaways
- URL structure should mirror the site's topical hierarchy: Hub → Pillar → Spoke
- Important pages should stay within 3 folder levels of the root
- Pages in the same SILO share a URL prefix; different SILOs should not nest inside each other
- GET parameters for core navigation and unnecessary date-based paths both hurt structure clarity
- Any URL structure change requires 301 redirects to preserve link equity