A Progressive Web App (PWA) is a web application that can be installed on a device, work offline and feel like an app, yet is built with web technologies and delivered through a URL. It sits between a website and a native mobile app.
In this guide we explain what a PWA is, how it works, its core components (web app manifest, service worker, caching strategies), how it works offline and installs, how it differs from a normal website, responsive design, native and hybrid apps, its advantages and disadvantages, which projects suit it, how to build one and what to test.
What Does PWA Mean?
PWA is short for Progressive Web App. In Turkish it can be called “ilerlemeli web uygulaması” or “aşamalı web uygulaması.”
How Does a Progressive Web App Work?
A PWA combines HTTPS, a manifest, a service worker and caching to load quickly, work with weak or no connection and offer an app-like experience on supported devices.
Core Components of a PWA
The Web App Manifest
A JSON file that gives the browser information about the app: name, icons, start URL, display mode and theme colors.
The Service Worker
A JavaScript layer that runs between the browser and the network and can manage caching, offline use and some background features.
The Service Worker Lifecycle
Register, install, activate and update. A new version waits until old tabs are closed unless you handle activation deliberately.
Caching Strategies
- Cache first: serve from cache, fall back to network.
- Network first: try the network, fall back to cache.
- Stale while revalidate: serve cached content immediately and refresh it in the background.
- Network only.
- Cache only.
| Strategy | Best for |
|---|---|
| Cache first | Static assets |
| Network first | Fresh data |
| Stale while revalidate | Content that can be slightly old |
| Network only | Always-live data |
| Cache only | Fixed offline resources |
How Does a PWA Work Offline?
Cached pages and data can be shown without a connection. Plan which pages and actions must work offline, and provide a clear offline page.
Can a PWA Be Installed?
Yes, on supported browsers and operating systems it can be added to the home screen or app menu.
Is a PWA Downloaded from an App Store?
It can be used directly from a URL, and with suitable methods it can also be published in some app stores.
PWA vs. Other Approaches
- PWA vs. a normal website: a PWA can install, work offline and send notifications.
- PWA vs. responsive web design: responsive design only adapts layout; it doesn’t make a site a PWA. See responsive web design.
- PWA vs. native mobile app: native apps have fuller device access; PWAs have one codebase and no store requirement.
- PWA vs. hybrid app: hybrid apps wrap web code in a native shell. See Flutter and commonly used software architectures.
Advantages of PWAs
- A single codebase.
- No store requirement.
- Lower development cost.
- Fast updates.
- Offline and poor-connection support.
- Fast opening.
- Search engine visibility.
- Home screen access.
- Low storage needs.
Disadvantages of PWAs
- Browser and operating system differences.
- Limited access to device features.
- Limited visibility in app stores. See Google Play Store SEO.
- Complex offline data management.
- Stale cache problems.
- Limits in heavy graphics work.
Which Projects Suit a PWA?
Content sites, e-commerce, dashboards, booking and service apps and tools that benefit from installability and speed. See what is e-commerce software and e-commerce SEO. They may not suit apps needing deep hardware access or intensive graphics.
How to Build a PWA
- Define user needs.
- Plan the architecture.
- Prepare a responsive interface.
- Use HTTPS.
- Prepare the manifest file.
- Create the service worker.
- Prepare an offline page.
- Plan push notifications.
- Test the PWA on real devices and with Google PageSpeed Insights.
SEO Considerations
Keep pages crawlable, URLs clean and canonical, and content indexable. See technical SEO, what is indexing, sitemap, canonical URL, Largest Contentful Paint, CDN and interaction design. For help, see our web design and SEO consulting services.
Frequently Asked Questions
What is a PWA?
A web application developed with web technologies that can be installed on supported devices, work offline and offer an app-like look.
What does PWA stand for?
Progressive Web App.
What does PWA mean in Turkish?
It can be expressed as “ilerlemeli web uygulaması” or “aşamalı web uygulaması.”
How does a PWA work?
A web app can use a manifest, a service worker, HTTPS and caching technologies together.
Is every website a PWA?
No. Mobile compatibility alone isn’t enough to be a PWA.
Can a PWA be installed on a phone?
On supported browsers and operating systems it can be installed to the home screen or app menu.
Is a PWA downloaded from an app store?
It can be used directly via a URL. With suitable methods it can also be published in some app stores.
Does a PWA work without internet?
Fully or partly, depending on the offline features built.
What is a service worker?
A JavaScript layer that works between the browser and the network and can manage caching, offline use and some background features.
