A multi-page site spreads authority across 20+ URLs. A one-page site concentrates all signals—backlinks, engagement, freshness, and topical authority—onto a single URL. This is a constraint and an advantage.
The constraint: you cannot segment keyword intent across separate pages. A law firm with a one-page site cannot dedicate one page to "injury law" and another to "employment law." Both topics live on the same URL.
The advantage: one-page sites rank faster when properly optimized because Google doesn't have to crawl and evaluate multiple pages. Authority signals don't dilute across a site structure. A single-page site with 100 quality backlinks concentrates all that link equity on one URL. A 20-page site with the same 100 backlinks spreads that equity across 20 pages—each gets 5 links on average.
In our experience working with one-page websites, the sites that rank well share a common trait: they treat the page like a micro-site with distinct content sections, not a glorified homepage. Each section targets a related keyword or subtopic. Navigation between sections uses anchor links. This structure signals to Google that the page covers a topic comprehensively.