Progressive Web Apps: What They Are and When You Need One

When clients ask about mobile apps, we often explore whether a Progressive Web App (PWA) might serve their needs better than a traditional native app. PWAs occupy an interesting middle ground—web technologies with app-like capabilities—that suits many use cases while avoiding the complexity of native development.

What Is a Progressive Web App?

A Progressive Web App is a website that uses modern web capabilities to deliver an experience similar to a native mobile application. The key technologies that enable this are:

Service Workers: JavaScript that runs in the background, enabling offline functionality, push notifications, and background synchronisation.

Web App Manifest: A JSON file that tells browsers how to display the app when installed—its name, icon, colours, and display mode.

HTTPS: Secure connections are required for service workers and many modern web features.

When a user visits a PWA, they experience it as a normal website. But they can also "install" it to their home screen, after which it launches like an app—without browser chrome, with its own icon, potentially working offline.

What PWAs Can Do

Modern PWAs have impressive capabilities:

Offline Functionality

Service workers can cache assets and data, allowing the app to function without an internet connection. Users can browse previously-viewed content, complete forms for later submission, or use tools that don't require server communication.

Home Screen Installation

Users can add the PWA to their home screen on mobile or desktop. It then appears alongside native apps, launching in its own window without browser interface.

Push Notifications

PWAs can send push notifications to re-engage users, just like native apps. Order updates, messages, reminders—anything that benefits from proactive communication.

Background Sync

If a user completes an action while offline (submitting a form, for example), background sync can automatically complete the action when connectivity returns.

Hardware Access

Modern browsers expose increasing hardware capabilities: camera, microphone, geolocation, Bluetooth, USB devices. Many apps that once required native development can now be built as PWAs.

Performance

With proper caching strategies, PWAs can load nearly instantly on repeat visits. The shell of the application loads from cache while fresh content fetches in the background.

Advantages Over Native Apps

PWAs offer several compelling advantages compared to native mobile applications:

Cross-Platform by Default

A single PWA works on iOS, Android, Windows, macOS, and any other platform with a modern browser. Native apps require separate development for each platform—effectively doubling development and maintenance costs.

No App Store Gatekeeping

Publishing a PWA means deploying to a web server. There's no app store review process, no 30% revenue share on in-app purchases, no waiting days for updates to be approved. You control your release schedule entirely.

Discoverability

PWAs are indexed by search engines like any website. Users can discover your app through Google, not just browsing the app store. Links can point directly to any screen within your app.

Lower Development Cost

Web development is generally more efficient than native development, and you're maintaining one codebase instead of two or three. This translates to lower initial development and ongoing maintenance costs.

Instant Updates

When you update a PWA, users get the new version immediately (or on next launch). No waiting for users to download updates, no supporting multiple versions simultaneously.

Easier to Try

Users can try your app by visiting a URL—no installation required. The friction-free initial experience often improves acquisition compared to "download our app."

Limitations of PWAs

PWAs aren't suitable for everything. Important limitations include:

iOS Restrictions

Apple has historically limited PWA capabilities on iOS. While support has improved, some features available on Android don't work on iPhones. Push notifications on iOS only became available in 2023. Storage limits are more restrictive. Apple has no obvious incentive to improve this, given it would reduce App Store revenue.

Hardware Access Limits

While web APIs expose many hardware capabilities, some remain native-only. Certain Bluetooth features, advanced camera controls, and deep OS integrations may not be possible.

Performance Ceiling

For extremely performance-intensive applications—complex 3D games, heavy video processing, real-time audio manipulation—native code still has advantages. The gap has narrowed dramatically, but it exists.

App Store Presence

Some users expect to find apps in the app store. While PWAs can be wrapped for app store distribution (using tools like PWABuilder), they're not natively discoverable there.

Offline Complexity

Building robust offline functionality requires careful architecture. What happens when offline changes conflict with server changes? How much data should be cached? Offline-first development is more complex than always-connected applications.

When PWAs Make Sense

PWAs are often the right choice when:

You need mobile presence but not app store presence: For internal tools, B2B applications, or cases where users will install from your website rather than searching the app store.

Budget constraints preclude native development: If you can't afford to build and maintain iOS and Android apps separately, a PWA delivers much of the benefit at a fraction of the cost.

Content consumption is the primary use case: News, blogs, catalogues, documentation—content-focused applications work excellently as PWAs.

You already have or need a website: If you're building a website anyway, the incremental cost to make it a PWA is modest. You get app-like capabilities as a bonus.

Offline capability matters: Field service workers, retail environments with spotty connectivity, travel applications—anywhere users might lack reliable internet.

Rapid iteration is important: If you need to deploy updates frequently without app store delays, PWAs give you complete control.

When Native Apps Are Better

Native apps remain the right choice when:

App store discovery is essential: Consumer apps that depend on app store browsing for acquisition may need native presence.

You need iOS push notifications reliably: While technically possible now, iOS PWA push notifications have limitations and aren't as established as native.

Deep OS integration is required: Widgets, watch apps, Siri integration, Apple Pay in-app—features that deeply integrate with the operating system require native development.

Performance is critical: Games, AR/VR, real-time multimedia processing—applications pushing hardware limits may need native optimisation.

Your audience expects an app: Sometimes market expectations matter. If your competitors have polished native apps, a PWA might be perceived as inferior regardless of actual capability.

Building a PWA

If you're considering a PWA, the good news is that modern frameworks make it straightforward. SvelteKit, for example, can be configured as a PWA with relatively modest additional effort. The core work is designing your caching strategy and ensuring the app works well offline.

For simpler needs, a basic PWA can be added to an existing website. For more ambitious applications with rich offline functionality, dedicated development effort is required.

We've built PWAs for various purposes—internal tools, customer portals, content applications. If you're wondering whether a PWA suits your needs, get in touch. We're happy to discuss your requirements and recommend the most appropriate approach.