Web app vs mobile app: what’s the difference and which do you need?

October 26th, 2026 at 08:11 am

By Ronak Shah, Nordstone  |  Last updated: October 2026

A web app runs in a browser and needs no download. A mobile app is installed from an app store and can use the phone’s hardware. For most UK businesses, start by validating the business need; then choose a web app, PWA or native/cross-platform app based on capability, usage and distribution requirements.

TL;DR

• The difference: a web app lives in a browser at a web address; a native mobile app is installed from a store and can use Bluetooth, sensors and background tasks.
• progressive web appWeb Push The middle path: a progressive web app (PWA) can be installed from the browser, support selected offline features and send push notifications on supported devices. On iPhone, Web Push is available to web apps added to the Home Screen.
• UK Public-sector context: GOV.UK Service Manual guidance is written for government services, not as a universal rule for commercial businesses. It can be useful background on mobile service design, but commercial teams should choose based on user needs, product requirements and evidence from their own customers.
• Store rules: Apple’s guideline 4.2 expects an app to go beyond a repackaged website, so a plain wrapper risks rejection.
• UK cost guide Cost: Nordstone’s published UK guide gives indicative ranges of £1,500–£10,000 for a professional small-business website, £8,000–£25,000 for a PWA, and £15,000–£100,000+ for a native or cross-platform app. These are planning ranges, not fixed quotes; scope and integrations change the final price.
• Ofcom Habit check: Ofcom’s research on UK online behaviour can provide context about smartphone use, but broad app-usage averages do not prove that customers will adopt a particular product.

What is the difference between a web app and a mobile app?

A web app is software people access through a browser at a web address. A mobile app is installed on a phone, commonly through an app store. This article focuses on the technical and product trade-offs between those options; our broader guide, [App vs website: does your UK business actually need an app?], helps decide whether a business needs an app at all.

A web app lives at a web address. A customer can open it from a Google result or a link in a text message, and you can update it for everyone at once without anyone doing anything. A mobile app, usually called native when it is written for iOS or Android, sits on the phone itself. It can reach Bluetooth, the camera, motion sensors and background location in ways a browser either can’t or does inconsistently, and it gets a home-screen icon and a store listing along the way. The catch is that someone has to go and download it.

whether your UK business needs an app or a websiteFor the broader business question—whether you need a website, app or PWA—see our [App vs website guide]. This article has a narrower role: explaining web-app and mobile-app capabilities, practical limits and the cost implications of each route.

What is a progressive web app, and where does it fall short?

Google’s web.dev A progressive web app (PWA) is a web app enhanced so it can be installed on a home screen, cache selected content for offline use and, where supported, send push notifications. It combines web distribution with some app-like capabilities, but browser and operating-system support varies. For a deeper native-versus-cross-platform-versus-PWA decision framework, see our [Native vs Cross-Platform vs PWA guide].

On Apple devices the notification part deserves a closer look. WebKit’s team added Web Push in iOS and iPadOS 16.4, but for web apps added to the Home Screen, triggered by a direct tap, and only after the user agrees to a permission prompt. Each of those steps loses people along the way.

That is the honest weakness of a PWA. It can do the job, but the install journey is tucked into a share menu rather than a store people already trust. Apple keeps changing this area, so check what Safari supports today before you promise anyone a feature.

When does a web app make more sense than a mobile app?

Choose a web app when people will use the thing now and then, from whatever device they happen to have. Booking systems, quote calculators, customer portals, internal dashboards and most B2B tools fit this description. Nobody wants to download an app to check an invoice twice a year.

Service ManualFor public services, GOV.UK’s Service Manual recommends checking whether a responsive website or PWA meets the need before commissioning a native app. That guidance is specifically for public services, not a blanket recommendation for commercial businesses. For a commercial product, compare customer needs, frequency of use, device capabilities, accessibility, acquisition channels and total cost of ownership. A browser-based option may be simpler to maintain, but it is not automatically right for every business.

[Nordstone data point to verify before publishing: share of client discovery calls in the last 12 months where we recommended a web app or PWA first, and why.]

When do you genuinely need a native mobile app?

For public services, GOV.UK’s Service Manual describes situations where a native app may be justified, such as when a service needs a persistent presence on a user’s device, particular device features, or reliable offline data collection. Commercial businesses can use these as prompts, but should also consider their own users, product goals, store-discovery strategy and evidence of repeat demand.

Picture a courier driver logging proof of delivery in a basement car park, a fitness app reading a heart-rate strap over Bluetooth, or a banking app that leans on biometric sign-in and background alerts. Add a commercial reason too: some products depend on being found in the App Store, or on living on the home screen of people who open them daily.

That last point is where founders fool themselves. Ofcom’s Online Nation report says UK adults spend about four and a half hours online a day, mostly on smartphones, using an average of 41 apps a month. That tells you phones matter. It doesn’t tell you customers will hand one of those 41 slots to you. If you can’t picture weekly use, hold off.

How do web apps, progressive web apps and native apps compare?

The comparison below summarises the trade-offs at a glance. Costs are relative in the table; see the next section for indicative UK build ranges and their limitations.

Image 1: the three options on one line. Cost and effort rise as you move towards native.

The table’s cost labels are relative, not quotes. Indicative UK ranges are provided below for context; browser and operating-system support changes, so test any capability the product depends on before committing.

Can you just wrap your website in an app?

You can, and some agencies will happily sell you one, but it is the riskiest shortcut on this page. Apple’s App Review Guidelines say in 4.2 that an app should include features, content and UI that elevate it beyond a repackaged website. Guideline 4.2.2 adds that, apart from catalogues, apps shouldn’t primarily be marketing materials, web clippings, content aggregators or a collection of links.

If a wrapper is genuinely all you need, you probably wanted a PWA. If the store listing matters, plan for a handful of features that need the device, such as push, biometric sign-in, a camera flow or offline caching. Our App Store and Google Play launch guide walks through accounts, assets and the review process.

How much does each option cost in the UK?

how much it costs to build an app in the UK Indicative planning ranges vary with complexity, design, integrations, security and delivery team. Nordstone’s published UK guides give the following broad estimates: a professional small-business website typically costs £1,500–£10,000; a progressive web app typically costs £8,000–£25,000; and a native or cross-platform mobile app typically costs £15,000–£100,000+. For native builds, Nordstone’s cost guide estimates £15,000–£30,000 for a simple single-platform app, £30,000–£70,000 for medium complexity and £70,000 or more for a complex app. A second native platform can add 70%–90%. These figures are planning ranges, not guaranteed prices; compare proposals for the same scope.

Developer Program A web app or PWA can reduce the need for separate platform-specific front ends, but it is not automatically cheaper for every feature set. Native publishing also has store fees and review requirements. Compare the full cost of discovery, build, hosting, security, maintenance, analytics and future feature work—not just the first development quote.

Cost source: Nordstone’s [App vs website guide] gives the website and PWA ranges; the [UK mobile app development cost guide] gives native-app ranges. Treat both as indicative planning estimates and confirm the current figures on the live pages before publishing.

How do you decide which one you need?

Work through three questions in order, as shown in the diagram. Does the product require device capabilities or background processing that browsers cannot reliably provide? If yes, consider native or cross-platform after technical discovery. If not, will people use it regularly and benefit from a home-screen experience, notifications or offline support? If yes, assess a PWA. If browser access and search discovery are enough, a responsive web app may be the simplest option. App-store discovery can also affect the decision.

Image 2: a simplified decision path. Regulated or high-security products need a proper discovery phase.

validating your app idea before you buildfree tools for planning and building your app A practical test is to map a customer’s typical week and identify when they would use the product. If use is infrequent and browser access is sufficient, start with a web app. If repeat use, home-screen access or offline capability matters, evaluate a PWA. If you need deeper device integration or store distribution, compare native and cross-platform options. Our [validate your app idea guide] and [free tools for planning an app] can help test demand before committing budget.

Can you start with a web app and move to native later?

Yes, and for many businesses it is the sensible order. The trick is to put business logic and data behind an API from the start. The web front end can then use it today, and a native app can use the same back end later. What you rebuild is the interface, not the whole product.

Whichever route you take, settle ownership early. Our guide on who owns the code when you hire an app developer covers source code, accounts and licences, and it matters just as much for a web app as for a native one. If you are still weighing who should build it, see in-house vs agency vs freelancer.

[Nordstone data point to verify before publishing: share of client projects in the last 12 months that started as a web app or PWA and later added a native app.]

Frequently asked questions

Not sure which route fits your product?

app development brief template get in touch with Nordstone If you would like an outside view before committing budget, start with our app development brief template and then contact Nordstone. We can help compare a web app, PWA and native/cross-platform approach against your requirements.