Web app or mobile app:
which does your business need?
Short answer: Web app first if your users are desk-based, you're building B2B tools, or you want the fastest path to market. Mobile app first if you need device hardware, push notifications, or offline use. Many businesses start with one and add the other — we'll tell you which to build first.
Web app vs mobile app — compared
| Criteria | Web App | Mobile App |
|---|---|---|
| Access | Browser on any device — no install required | Downloaded from App Store / Google Play |
| Typical cost | £10,000–£60,000+ | £8,000–£80,000 (both platforms via cross-platform: from £12,000) |
| Time to launch | No approval — deploy immediately | App Store review: 1–7 days (iOS), 1–3 days (Android) |
| Offline use | Limited (PWA service workers) — tricky on iOS | Full offline capability |
| Device hardware | Limited camera/GPS via browser APIs | Full — camera, GPS, Face ID, NFC, push notifications, sensors |
| Push notifications | Android: yes via PWA | iOS: very limited | Full support on both platforms |
| Updates | Instant — no user action needed | Via App Store — user must update |
| User engagement | Lower — no home screen icon by default | Higher — home screen, push, habit-forming UX |
| Best for | B2B SaaS, internal tools, dashboards, marketplaces | Consumer apps, field tools, apps requiring device features |
Which is right for your use case?
Build a web app when:
- Users will be primarily on a desktop or laptop
- You're building a B2B SaaS platform or admin dashboard
- You want the fastest route to a working product
- Your budget is £10,000–£25,000 and you need both web and mobile covered (PWA is an option)
- The product doesn't need device hardware or push notifications
- You're replacing a spreadsheet or manual process
- Multi-tab workflows are part of the UX (reports, data tables, complex forms)
Build a mobile app when:
- Your users are primarily on iPhone or Android while on the move
- You need push notifications as a core engagement mechanic
- The product needs camera, GPS, NFC, biometric auth, or other hardware
- Offline functionality is required (field workers, remote locations)
- You're building a consumer-facing product (fitness, food, social, marketplace)
- You're targeting younger audiences who expect a native app experience
- App Store / Play Store distribution is part of your growth strategy
Often, you need both — but not at the same time.
The typical journey
Most businesses with a digital product follow the same path: build the web app first to validate the core product, acquire early users and iterate on feedback. Once product-market fit is established and you understand what mobile users need, add the mobile app.
This is dramatically cheaper than building both in parallel — and avoids building mobile features for assumptions that turned out to be wrong.
How we architect for both
When we build a web app that will eventually need a mobile companion, we architect the backend API to support both from day one. Adding a mobile frontend later is then a clean separate project — no rework of the backend, data model or business logic.
Cost: mobile layer on an existing API is typically 40–60% cheaper than building from scratch.
Common questions
What is the difference between a web app and a mobile app?
A web app runs in a browser — no install required. A mobile app is downloaded from the App Store or Google Play and runs natively on the device. Mobile apps have full hardware access; web apps are universally accessible.
Is a web app cheaper to build?
Generally yes — web apps start from £10,000 and don't require App Store approval. Mobile apps start from £8,000 per platform. Cross-platform mobile (React Native/Flutter) covers both for similar cost to one native app.
Can a Progressive Web App (PWA) replace a mobile app?
PWAs work well on Android. On iOS, they have meaningful limitations — limited push support, restricted hardware access, lower user engagement. For most consumer products, a native app still delivers a better experience on iOS (over 50% of UK smartphone market).
Should a startup build a web app or mobile app first?
Web app first in most cases — faster to build, easier to iterate, no App Store review delays. Add mobile once you've validated the core use case with real users. Exceptions: consumer-first products with strong mobile behaviour, GPS/camera-dependent use cases.
Read next
Web App Development London
Custom web applications for UK businesses — costs, stack, process and timelines.
Read more →Mobile App Development UK
iOS and Android app development for UK businesses — costs, platforms and timelines.
Read more →React Native vs Flutter
Decided on a mobile app? Now choose the right framework for your project.
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