PWA
A **Progressive Web App (PWA)** is a website or web app built with web technologies that can behave like a native app, including installability, offline support, and app-like user experience.
Key takeaways
- PWAs are websites that can be installed and work offline, using service workers and a web app manifest.
- They improve mobile UX and engagement, but SEO requires careful handling of JavaScript rendering.
- HTTPS is mandatory for PWA features.
- Test your PWA with Lighthouse and monitor indexing in Google Search Console.
- Start with a simple service worker and manifest, then progressively enhance.
PWAs combine the reach of the web with the capabilities of native apps, but their SEO success depends on careful implementation.
Example: Twitter Lite
- Twitter Lite is a well-known PWA that replaced the native Twitter app for many users.
- It loads quickly even on slow networks, supports offline reading of previously loaded tweets, and can be installed on the home screen.
- Despite being a web app, it feels native and retains full search engine discoverability.
When should I use a PWA?
- You want an app-like experience without building and maintaining separate native apps for iOS and Android.
- Your audience includes users with limited data or storage space — PWAs are lightweight and work offline.
- You need to improve mobile engagement, load speed, and user retention.
- You already have a functional website and want to enhance it progressively.
What a PWA is not
- Not a native app — PWAs run in a browser and cannot access all device APIs (e.g., Bluetooth, NFC).
- Not automatically SEO-friendly — Poor JavaScript rendering can block search engine crawlers.
- Not a replacement for a website — PWAs are websites first, with added capabilities.
- Not a single technology — PWAs are a set of best practices and technologies (service workers, manifest, HTTPS).
Quick start: How to make your site a PWA
- Serve your site over HTTPS — Required for service workers and many PWA features.
- Create a web app manifest — A JSON file that defines how your app appears when installed (name, icons, theme color, etc.).
- Register a service worker — A script that runs in the background to handle caching, offline support, and push notifications.
- Add a service worker to cache key assets — Start with a simple cache-first strategy for static files.
- Test with Lighthouse — Use Chrome DevTools Lighthouse audit to check PWA criteria and fix issues.
Common SEO mistakes with PWAs
- Assuming a PWA is automatically SEO-friendly — Always verify crawlability, rendering, and internal linking.
- Using client-side routing that hides content — Ensure all important pages have unique, crawlable URLs.
- Treating installability as the only goal — Focus on performance, offline support, and user experience first.
- Implementing offline caching without testing updates — Stale content can confuse users and search engines.
Next step
FAQ
What is a Progressive Web App in simple terms?
A PWA is a website that acts like a mobile app. It can be installed on your device, work offline, load quickly, and send push notifications — all without needing an app store.
Are PWAs good for SEO?
Yes, if correctly implemented. PWAs are still web pages and can be found by search engines. However, poor use of JavaScript or client‑side routing can cause indexing issues.
Do PWAs work on iOS?
Yes, but with limited features compared to Android. Apple added support for service workers and the manifest in iOS 16.4, but some APIs are still unavailable.
How do I install a PWA?
When you visit a PWA in a supported browser (like Chrome or Edge), you may see an install icon in the address bar. Click it to add the app to your home screen.
Related topics
Sources
- Google Search Central — Best source for SEO guidance on JavaScript rendering, crawlability, indexing, and mobile-friendly site behavior.
- web.dev PWA guidance — Google-maintained reference explaining the core PWA model, installability, offline support, and single-codebase behavior.
- MDN Web Docs — Clear technical definition of PWAs and the web platform features they rely on.
- Microsoft Learn — Useful implementation overview from a major browser/platform vendor.
Reviewed by Lucía Marín, Founding editor.