How to Build a PWA With SvelteKit

Progressive Web Apps (PWAs) combine the best of web and mobile apps, offering features like offline access, push notifications, and a native app-like experience. Building a PWA with SvelteKit can enhance user engagement and provide a fast, responsive interface. This guide walks you through the essential steps to create a PWA using SvelteKit.

1. Setting Up Your SvelteKit Project

To start, ensure you have Node.js installed on your system. Then, open your terminal and run the following command to create a new SvelteKit project:

npm init svelte@next my-sveltekit-pwa

Change into your project directory:

cd my-sveltekit-pwa

Next, install the necessary dependencies:

npm install

2. Configure the PWA Manifest

A web app manifest provides the browser with information about your app in a JSON format. Create a new file called manifest.json in your static directory:

{
  "short_name": "MyPWA",
  "name": "My Progressive Web App",
  "start_url": ".",
  "display": "standalone",
  "background_color": "#ffffff",
  "theme_color": "#3f51b5",
  "icons": [
    {
      "src": "icon-192x192.png",
      "sizes": "192x192",
      "type": "image/png"
    },
    {
      "src": "icon-512x512.png",
      "sizes": "512x512",
      "type": "image/png"
    }
  ]
}

Make sure to customize the values according to your app's needs.

3. Register the Service Worker

Service workers play a key role in enhancing a PWA's capabilities, enabling features like offline support and background sync. Create a new file named service-worker.js in the static directory:

self.addEventListener('install', (event) => {
  console.log('Service Worker installing.');
});
self.addEventListener('activate', (event) => {
  console.log('Service Worker activating.');
});
self.addEventListener('fetch', (event) => {
  event.respondWith(
    caches.match(event.request).then((response) => {
      return response || fetch(event.request);
    })
  );
});

Then, register the service worker in your root component (+layout.svelte):

<script context="module">
  export async function load() {
    if ('serviceWorker' in navigator) {
      await navigator.serviceWorker.register('/service-worker.js');
    }
  }
</script>

4. Enable Offline Support

To provide a seamless offline experience, you will need to add caching strategies to the service worker. Update your service-worker.js file to cache essential files during the install event:

self.addEventListener('install', (event) => {
  event.waitUntil(
    caches.open('my-pwa-cache').then((cache) => {
      return cache.addAll([
        '/',
        '/global.css',
        '/icon-192x192.png',
        '/icon-512x512.png',
      ]);
    })
  );
});

5. Testing Your PWA

To test your PWA, you can use Chrome's DevTools. Open your app in Chrome, then navigate to DevTools by right-clicking and selecting Inspect. Go to the Application tab, and check that your manifest and service worker are properly registered.

You can also enable offline mode in the DevTools. Click the three-dot menu on the top right, select More Tools, then Network Conditions. By unchecking 'Offline', you can see how your app responds in offline mode.

6. Deploying Your PWA

Once satisfied with your PWA, it's time to deploy. Many platforms like Vercel, Netlify, or Firebase Hosting make deployment easy. Simply run the following command for static site generation:

npm run build

Upload the generated

How to Build a PWA With SvelteKit