What Is PWA?
Progressive Web App
A PWA is a web application that uses modern browser APIs to deliver app-like experiences — offline support, push notifications, and home screen installation — without requiring app store distribution.
How PWA Works
PWAs use service workers to cache assets and enable offline access, a web app manifest for install prompts, and HTTPS for security. Twitter Lite, Starbucks, and Pinterest all launched successful PWAs that matched or exceeded their native app metrics.
The key advantage: one codebase reaches all platforms. Users can install a PWA from the browser without going through app stores, and updates deploy instantly like websites.
Key Concepts
- Service Worker — A background script that caches resources and enables offline functionality
- Web App Manifest — A JSON file that defines the app's name, icons, and theme for home screen installation
- Installable — Users can add a PWA to their home screen and launch it like a native app
Frequently Asked Questions
Can a PWA replace a native app?
For many use cases, yes. PWAs can work offline, send push notifications, and access device APIs. But they can't access all native features (Bluetooth, NFC on iOS) and aren't listed in app stores by default.
Do PWAs work on iOS?
Yes, but with limitations. Safari supports service workers and home screen installation, but push notifications on iOS only arrived in 2023 and some APIs remain restricted.