Why the Distinction Matters
"We need a website" is one of the most ambiguous briefs a developer can receive. It could mean a 5-page marketing site that should be live in two weeks, or it could mean a full SaaS dashboard with authentication, billing, and data visualisation. The build approach, timeline, cost, and maintenance burden are completely different.
Getting this wrong is expensive. Companies that treat a web app as a website end up with a fragile CMS-built product that breaks under real usage. Companies that treat a website as a web app spend 10x more than necessary on a contact page.
What Is a Website?
A website is primarily informational. Its job is to communicate and convert — explain what you do, why you're credible, and prompt visitors to take a specific action (buy, book, contact, download).
Characteristics:
- Mostly static content (doesn't change per user)
- No or minimal user accounts
- Content managed by non-developers
- Primary metric is conversion rate, not engagement time
Technology fit: Next.js with a headless CMS (Sanity, Contentful, or even Notion), or a static site generator. Server-side rendering for SEO. A CDN for performance.
What Is a Web App?
A web app is primarily functional. Its job is to let users accomplish tasks — track shipments, manage invoices, collaborate on documents, book appointments, or analyse data.
Characteristics:
- Dynamic, user-specific content
- Authentication and user accounts required
- State management across sessions
- Primary metric is task completion rate and retention
Technology fit: React or Next.js with a proper backend (Node.js, PostgreSQL), authentication (Supabase Auth, Auth.js), and real-time capabilities if needed.
The Grey Area: Marketing + App
Most modern businesses need both. A SaaS product has a marketing site (the landing page, pricing, blog) and a web app (the dashboard users log into). These are usually separate codebases, occasionally combined in a monorepo.
The mistake is trying to build both in the same architecture from day one. Start with the marketing site to validate your positioning and drive sign-ups. Build the app in parallel or subsequently. Keep them deployable independently.
Decision Framework
Ask these four questions:
1. Does each user see different content?
If yes → web app. If no → website.
2. Do users need to create accounts and log in?
If yes → web app. If no → probably a website (or a website with a simple form integration).
3. Will non-developers update the content regularly?
If yes → website with a CMS. If no → static site or hardcoded content is fine.
4. Does the content drive business decisions in real time (orders, bookings, inventory)?
If yes → web app with a real database. If no → a website with form integrations is sufficient.
Cost and Timeline Implications
A well-executed marketing website: 2–4 weeks, depending on design complexity and content.
A web app MVP: 6–12 weeks minimum, assuming a defined scope.
A web app with full authentication, billing, and a data layer: 3–6 months for a team of two.
These aren't estimates — they're industry baselines. Compressing timelines requires either reducing scope or increasing the team.
The SEO Dimension
Websites need to rank. Web apps usually don't (you're not trying to get Google to index your user dashboard).
This affects technology choice: server-side rendering or static generation is critical for marketing sites. For web apps, client-side rendering is often fine (though SSR still has benefits for SEO if you have public-facing app pages).
If your web app has public content — a marketplace with product listings, a job board, a directory — treat those public pages like a website and ensure they're server-rendered and indexable.
My Recommendation
When in doubt, ship the website first. A polished marketing site with a working contact form can validate your business thesis in weeks. Once you have paying customers, you know exactly what to build next.
Need help deciding what to build — and building it? Let's talk →