ScrollLaunchpadJobsSearchBlog

Jagadhiswaran Devaraj

Mar 19, 2025 • 6 min read

Progressive Web Apps (PWAs): The Future of Fast, Reliable, and Cross-Platform Web Experiences

How PWAs Outperform Traditional Web and Native Apps with Speed, Offline Access, and Cost-Effective Development

If you’ve ever built a web app, you might have thought: "It’s mobile-responsive, so why do I need a PWA?" That’s a fair question. A normal web app works on mobile, but PWAs take things further. They work offline, load faster, send push notifications, and can even be installed like a native app.

With modern frameworks like Next.js and React, building PWAs has become even more seamless. These frameworks provide built-in optimizations, automatic static generation, API routes, and service worker integration, making it easier to build scalable and high-performance PWAs.

So let’s break this down. Why are PWAs faster, better, and more efficient than normal web apps? And more importantly, how can you optimize your web app to become a PWA? Let's get into the details.

The Key Difference Between a Normal Web App and a PWA

A normal web app is built with HTML, CSS, and JavaScript and runs entirely in a browser. It depends on an internet connection, meaning if the network drops, the app stops working.

A PWA, on the other hand, uses Service Workers, Caching, and a Web App Manifest to:

  • Work offline

  • Load faster

  • Send push notifications

  • Be installed on a phone or desktop

Let’s compare the basic structure of a normal web app vs. a PWA.

Normal Web App Example

Here’s what a simple web app might look like:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Normal Web App</title>
</head>
<body>
    <h1>Welcome to My Web App</h1>
    <p>This web app works only when online.</p>
</body>
</html>

This works fine, but the moment the user loses connectivity, the page fails to load.

PWA Example (without framework)

A PWA introduces a Service Worker to handle caching and offline capabilities. Here’s how you modify the above web app into a PWA.

1. Create a Service Worker

A Service Worker is a script that runs in the background and intercepts network requests, allowing caching and offline functionality.

// service-worker.js
self.addEventListener("install", event => {
    event.waitUntil(
        caches.open("app-cache").then(cache => {
            return cache.addAll([
                "/", "/index.html", "/styles.css", "/script.js"
            ]);
        })
    );
});

self.addEventListener("fetch", event => {
    event.respondWith(
        caches.match(event.request).then(response => {
            return response || fetch(event.request);
        })
    );
});

2. Register the Service Worker in Your App

<script>
    if ('serviceWorker' in navigator) {
        navigator.serviceWorker.register('/service-worker.js')
            .then(() => console.log('Service Worker Registered'))
            .catch(err => console.log('Service Worker Registration Failed', err));
    }
</script>

3. Add a Web App Manifest

This tells the browser how the app should behave when installed.

{
    "name": "My PWA",
    "short_name": "PWA",
    "start_url": "/index.html",
    "display": "standalone",
    "icons": [
        {
            "src": "icon.png",
            "sizes": "192x192",
            "type": "image/png"
        }
    ]
}

PWA Example with Next.js

If you're using Next.js, you can easily turn your app into a PWA using the next-pwa package, which enables service worker support.

1. Install Dependencies

npm install next-pwa

2. Update next.config.js to Enable PWA Support

const withPWA = require("next-pwa");

module.exports = withPWA({
    pwa: {
        dest: "public",
        register: true,
        skipWaiting: true,
    },
});

3. Add a Web App Manifest

Next.js allows serving static assets from the public folder. Place a manifest.json file in public/manifest.json.

{
    "name": "My PWA",
    "short_name": "PWA",
    "start_url": "/",
    "display": "standalone",
    "icons": [
        {
            "src": "/icons/icon-192x192.png",
            "sizes": "192x192",
            "type": "image/png"
        }
    ]
}

Why PWAs Load Faster and Perform Better

  1. Caching Reduces Load Time

    • In a normal web app, every request to the server fetches resources, increasing load time.

    • PWAs use caching strategies to store assets locally, reducing the number of network requests.

  2. Offline Functionality

    • Traditional web apps fail when offline.

    • PWAs serve cached versions of the app, ensuring usability even without an internet connection.

  3. Lower Bandwidth Usage

    • Normal web apps reload everything on each visit.

    • PWAs load only new or updated content, making them data-efficient.

Advanced Performance Optimizations in PWAs

  1. Lazy Loading & Code Splitting

    • Instead of loading the entire app at once, lazy loading ensures that only the necessary components are loaded initially, improving speed.

    • Code splitting divides the JavaScript bundle into smaller, manageable chunks that load as needed.

  2. Pre-Caching for Instant Load Times

    • Service workers can pre-cache key assets so that the app loads instantly, even on slow networks.

  3. Background Sync for Data Handling

    • Allows the app to sync data when connectivity is restored, ensuring no data loss for offline users.

  4. IndexedDB for Persistent Storage

    • Unlike traditional caching, IndexedDB allows PWAs to store complex data structures locally, enhancing offline experiences.

Future of PWAs

  1. PWAs & Project Fugu

    • Project Fugu is a Google initiative that adds missing native features (like file system access, clipboard API, etc.) to PWAs, making them even more powerful.

  2. PWAs and WebAssembly (WASM)

    • WebAssembly allows PWAs to run near-native performance, making them viable alternatives to traditional desktop applications.

  3. The Growth of PWAs on iOS

    • Apple has been slow to adopt full PWA support, but recent updates have improved offline capabilities and push notifications for iOS users.

Why Not a Native Mobile App Instead of a PWA?

At this point, you might be wondering, why not just build a native mobile app? After all, native apps provide the best user experience, work offline, and can access device features like cameras and sensors. However, there are several reasons why a PWA might be the better choice:

  1. No App Store Dependence

    • Native apps must go through app store approvals, which can be time-consuming and restrictive.

    • PWAs can be installed directly from the browser without requiring any store approval.

  2. Cross-Platform Compatibility

    • A native app requires separate codebases for iOS and Android.

    • A PWA runs on any device with a browser, reducing development effort.

  3. Lower Development Cost

    • Building and maintaining separate native apps for different platforms increases costs.

    • A single PWA codebase can serve multiple platforms with minimal overhead.

  4. Instant Updates

    • Native apps require users to update manually through the app store.

    • PWAs automatically update in the background, ensuring users always get the latest version.

  5. SEO and Discoverability

    • Native apps aren’t indexed by search engines.

    • PWAs are web-based and can be indexed, making them more discoverable through organic search.

  6. Faster Installation

    • A native app requires downloading from an app store, which can be slow and take up significant storage.

    • PWAs install instantly without consuming much device space.

Why Not a Desktop App Instead of a PWA?

Similarly, for desktop users, some might consider using frameworks like Electron or Tauri to build a native desktop app. While these frameworks have their advantages, PWAs still offer benefits that make them an attractive choice.

  1. Less Resource Consumption

    • Electron apps bundle Chromium, making them heavy on system resources.

    • PWAs rely on the browser’s built-in engine, consuming far fewer resources.

  2. No Installation Hassle

    • Desktop apps require users to download and install software.

    • PWAs can be accessed instantly from the browser and installed with a single click.

  3. Security Advantages

    • PWAs run in a sandboxed environment within the browser, reducing security risks.

    • Native apps require users to grant permissions, increasing potential vulnerabilities.

Real-World Impact of PWAs

  • Twitter Lite reduced load time by 30% and saw a 65% increase in page sessions.

  • Starbucks PWA is 99.84% smaller than its native counterpart and works offline.

  • Uber PWA loads in under 3 seconds on low-end devices.

Final thoughts

PWAs are no longer just an alternative; they are becoming a necessity for modern web applications. By leveraging service workers, caching strategies, background sync, and IndexedDB, they deliver a seamless and high-performance experience across devices. With the ongoing advancements in Project Fugu, WebAssembly, and improved iOS support, the future of PWAs looks even more promising. Whether you’re building for mobile or desktop, investing in a PWA can lead to better performance, reduced costs, and a broader reach compared to native applications.

- Jagadhiswaran Devaraj

📢 Stay Connected & Dive Deep into Tech!

🚀 Follow me for hardcore technical insights on JavaScript, Full-Stack Development, AI, and Scaling Systems:

🐦 X (Twitter): jags

✍️ Read more on Medium: https://medium.com/@jwaran78

💼 Connect with me on LinkedIn: https://www.linkedin.com/in/jagadhiswaran-devaraj/

Let’s geek out over code, architecture, and all things in tech! 💡🔥

Join Jagadhiswaran on Peerlist!

Join amazing folks like Jagadhiswaran and thousands of other people in tech.

Create Profile

Join with Jagadhiswaran’s personal invite link.

2

5

2