Websites that install like apps

Short answer

A progressive web app is a website that can install itself: it declares a manifest, registers a service worker, and the browser then offers it a home-screen icon and its own window with no address bar. Unlike a bookmark, an installed site can cache its own code and keep running with no connection. Excalidraw, Photopea, DevDocs, Lichess and Organic Maps are all ordinary websites by URL and installed applications once you accept the prompt.

What separates one of these sites from a bookmark

A bookmark is a pointer. An installed site is a copy of the app's code sitting on your device, managed by a service worker — a small script the browser keeps running even when no tab is open.

That difference is what produces the visible behaviours: its own window with no address bar, an icon among your other applications, and pages that render before the network answers, or without the network answering at all.

Mentioned here: ✏️ Excalidraw, 📚 DevDocs, 🖼️ Photopea

Sites where installing changes the experience

DevDocs is the clearest: the whole reference set is cached, so it answers instantly and offline. Excalidraw keeps your drawings local. Organic Maps is built for the case where the connection is gone.

Photopea is a different argument — it does not need offline so much as it needs a window of its own, because it behaves like a desktop image editor and an address bar above it is noise.

Sites where installing changes nothing much

Plenty of well-known sites offer to install and then behave exactly as they did in a tab. A site that fetches everything from a server on every view has nothing to cache, so installing it buys an icon and no resilience.

That is not dishonest, and it is not rare — we opened 646 of these and a majority install correctly then show nothing once the network drops. The measurement is here.

Frequently asked

Is a PWA just a website?

It is a website with two additions: a manifest that describes how it should look when installed, and a service worker that can serve its files without the network. Everything else is the same site.

Does installing take disk space?

A few megabytes typically. Browsers also evict caches when storage runs low, so an app untouched for months may need one reconnection to fill again.