Web app or mobile app? A decision framework

Web apps win on speed and scale

Build a web app (a responsive Next.js app) if: you're starting out and need to move fast. Your users are on desktop and phone (and responsive design works). Your app needs frequent updates. You want to reach users globally without app-store approval.

Web advantages: a single codebase. Instant updates. Works on any device with a browser. Users don't download anything. Easier to hire for (more React engineers than Swift engineers).

Cost: a responsive web app costs $30,000–60,000 to build.

Mobile apps win on engagement

Build a mobile app (iOS + Android) if: your core users are on their phones 80%+ of the time. You need push notifications for engagement (essential for social, messaging, and fitness apps). You need native features: camera, location tracking, offline access.

Mobile advantages: higher engagement (push notifications, home-screen presence). Native features feel seamless. Users see it as more professional. A presence in app stores grants credibility.

Cost: native iOS + Android costs $80,000–150,000. React Native (one codebase) costs $50,000–100,000.

Do you need both? (Usually not at the start)

Start with web. Launch fast, learn from users. If your users request mobile features (push notifications, offline access, a home-screen icon), build mobile.

Why? Because most SaaS products are used on the phone occasionally (checking a dashboard, reports) and on desktop for work. Responsive web works for both.

Launching web and mobile together costs twice the money and twice the time.

Exception: social, messaging, fitness, and gaming apps live on mobile. Build native mobile from the start.

The responsive web app (your default choice)

Responsive web is the middle ground: not as fast as web-only but not as expensive as native. It works on desktop and phone. It updates instantly. No app-store gatekeeper.

How it works: build once with Next.js and Tailwind. On mobile, users can install it as a "Progressive Web App" (added to the home screen like a native app).

Capabilities: PWAs support push notifications (via service workers), offline access (via caching), and camera/location. 90% of native capability at 10% of the cost.

The decision matrix

A pre-seed founder testing an idea: web app. You need to move fast and learn.

B2B SaaS (a Slack clone, project management): web app. Business users work on desktop.

A social network or messaging app: mobile app. Push notifications are essential for engagement.

Food delivery or ride-hailing (like Uber): mobile app. The driver and user experience depend on instant push and location.

News or content: web app or PWA.

If you're still unsure: build web first.

The hidden cost of mobile

Building iOS and Android separately costs twice the money. But the ongoing cost is the killer. iOS and Android update twice a year. Your app needs updates (compatibility patches, new OS features). That's 2–4 days per release minimum.

With web, you deploy once and everyone sees the new version. No friction.

At the early stage (under $100,000 revenue), that ongoing cost is brutal. At the growth stage (millions in ARR), you have a dedicated mobile team. But at the early stage? Web is smarter.