What is a progressive web app (PWA)?

PWA: definition and core idea

Progressive web apps combine the reach of the web with the convenience of an app. They are developed with web technologies such as HTML, CSS, and JavaScript, run in the browser, and can also be used like an installed application—with their own icon on the home screen and no browser bar.

“Progressive” means that the application works in every modern browser and offers additional features wherever the device supports them. If you don't install the PWA, you simply keep using it as a website.

How a progressive web app works

Three technical building blocks turn a website into a PWA. Together, they enable installation, fast loading, and offline capability.

Support is comprehensive on Android and in desktop browsers such as Chrome or Edge. PWAs also work on iPhone and iPad, but with restrictions; web push notifications have only been available there since iOS 16.4, and only for web apps installed on the home screen.

• Web app manifest: the app's name, icon, colors, and launch behavior
• Service worker: a background script that caches content and enables offline use
• HTTPS: an encrypted connection as a prerequisite
• Optional: push notifications and background sync

Benefits and limitations of PWAs

A PWA is based on a single codebase for all platforms. Updates are available to all users immediately, with no app store approval process. At the same time, the application remains discoverable via search engines and shareable via link—an advantage that traditional apps don't have.

There are limits when it comes to accessing certain device features, very compute-intensive applications, and visibility in app stores. If you need to be present there, you can additionally package a PWA as an app or opt for a native or cross-platform app.

• One codebase for smartphone, tablet, and desktop
• No store approvals required for updates
• Discoverable via Google and shareable via link
• Limited access to some device features, especially on iOS

Real-world example: when a PWA makes sense

A service company wants to give its technicians mobile access to checklists and job data—even in a basement with no signal. A PWA stores the day's jobs locally, and entries are synced as soon as a connection is available again. Installation happens via a link, without going through an app store.

PWAs are particularly well suited for customer portals, booking and ordering applications, internal tools, and MVPs. In the initial consultation, Nano Concepts assesses whether a PWA covers your requirements or whether an app from the store is the better choice, and then implements the right solution.