Progressive Web Apps (PWAs) have become a game-changer in the world of web development, combining the best of web and mobile apps. PWAs offer fast, reliable, and engaging experiences that work offline and can be installed on devices just like native applications.
In this tutorial, I'll walk you through building a PWA using SvelteKit, a modern framework for building highly optimized web applications. SvelteKit's server-side rendering (SSR) and static site generation (SSG) make it an excellent choice for PWAs.
Why SvelteKit for PWAs?
SvelteKit offers a powerful combination of simplicity and performance. With SvelteKit:
- Simplicity: The reactive, component-based structure of SvelteKit makes it easy to build web apps.
- Performance: Svelte compiles your code to highly optimized JavaScript, leading to fast load times and minimal overhead.
- PWA Features: With SvelteKit, you can easily configure service workers and other PWA functionalities.
Step 1: Setting Up a New SvelteKit Project
First, let's create a new SvelteKit project.
Install Node.js: Make sure you have Node.js installed on your machine. You can download it here.
Create a new SvelteKit project:
npm create svelte@latest my-pwa-app
cd my-pwa-app
npm install
- Run the project:
npm run dev
This will start a development server and open the default SvelteKit project in your browser. You should see the "Welcome to SvelteKit" page.
Step 2: Setting Up the PWA Manifest
A PWA requires a web app manifest file, which provides metadata about your app (such as the name, icons, and theme colors). Let’s add this to your SvelteKit project.
-
Create a
manifest.jsonfile in thestatic/directory:
{
"name": "My PWA App",
"short_name": "PWA App",
"description": "A Progressive Web App built with SvelteKit",
"start_url": "/",
"display": "standalone",
"background_color": "#ffffff",
"theme_color": "#ff3e00",
"icons": [
{
"src": "/icons/icon-192x192.png",
"sizes": "192x192",
"type": "image/png"
},
{
"src": "/icons/icon-512x512.png",
"sizes": "512x512",
"type": "image/png"
}
]
}
Add some icons to your project by placing them inside a
static/icons/folder. You can generate icons of different sizes using tools like Real Favicon Generator.In your
src/routes/__layout.svelte, link the manifest and add meta tags for mobile and theme color:
<head>
<link rel="manifest" href="/manifest.json" />
<meta name="theme-color" content="#ff3e00" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
</head>
Step 3: Configuring Service Workers
A service worker enables your app to work offline by caching essential assets. Let’s configure it in SvelteKit.
-
Install the
vite-plugin-pwaplugin:
npm install vite-plugin-pwa --save-dev
-
Modify your
vite.config.jsto register the service worker:
import { defineConfig } from 'vite';
import { sveltekit } from '@sveltejs/kit/vite';
import { VitePWA } from 'vite-plugin-pwa';
export default defineConfig({
plugins: [
sveltekit(),
VitePWA({
registerType: 'autoUpdate',
manifest: {
name: 'My PWA App',
short_name: 'PWA App',
theme_color: '#ff3e00',
icons: [
{
src: '/icons/icon-192x192.png',
sizes: '192x192',
type: 'image/png'
},
{
src: '/icons/icon-512x512.png',
sizes: '512x512',
type: 'image/png'
}
]
},
workbox: {
runtimeCaching: [
{
urlPattern: /^https:\/\/fonts\.googleapis\.com\//,
handler: 'CacheFirst',
options: {
cacheName: 'google-fonts-stylesheets'
}
},
{
urlPattern: /^https:\/\/fonts\.gstatic\.com\//,
handler: 'CacheFirst',
options: {
cacheName: 'google-fonts-webfonts',
expiration: {
maxEntries: 30,
maxAgeSeconds: 60 * 60 * 24 * 365
}
}
}
]
}
})
]
});
Add offline caching strategies by configuring runtime caching for specific assets, such as fonts or API responses.
When you rebuild your project (
npm run build), the service worker will be generated automatically and registered in your app.
Step 4: Testing and Deploying Your PWA
You can now test your PWA features, including offline capabilities and installability.
-
Test the PWA in Chrome:
- Open Chrome DevTools.
- Go to the "Application" tab and look for the "Service Workers" section to verify that the service worker is active.
- You can also check the "Manifest" section to see if the PWA manifest is recognized.
-
Deploy the app:
- Deploy your app on platforms like Vercel, Netlify, or any static hosting provider.
- Once deployed, you can test the installation process by visiting your app on mobile and using the "Add to Home Screen" feature.
Conclusion
By following these steps, you've built a fully functional Progressive Web App using SvelteKit! You've seen how to integrate PWA features such as the app manifest and service workers into your SvelteKit project. PWAs are a great way to create fast, reliable, and engaging user experiences that work offline and feel like native apps.
Top comments (0)