Short answer: modern websites can work offline by becoming Progressive Web Apps (PWAs), which use a "service worker" to cache the site so it loads with no internet. As a user you can install these to use them offline; as a builder you add a service worker and a manifest. Here is how both sides work.
How a website can work offline
A service worker is a small script the browser runs in the background. It caches your site's files (HTML, CSS, JS, images) on first visit, so on later visits, even with no connection, the browser serves the cached version. That is how apps like some note-takers, games and readers open instantly and work on a plane.
For users: install offline-capable web apps
- Look for an Install icon in Chrome's address bar (or "Add to Home Screen" on mobile) on supported sites.
- Installed PWAs open like an app and often work offline.
- Great examples: offline-capable note apps, calculators, and reading tools.
For builders: the three pieces of a PWA
- HTTPS, service workers require a secure origin.
- A manifest file, a small JSON describing your app's name, icons and colors so it can be installed.
- A service worker, the script that caches files and serves them offline.
A basic service worker caches your core files on install and serves them from cache when the network is unavailable, dozens of free tutorials and tools (like Workbox) generate one for you.
What works offline and what does not
| Works offline | Needs internet |
|---|---|
| Cached pages and assets | Live data / new content |
| Local tools (calculators, editors) | Logins, syncing, fresh feeds |
The non-obvious tip: offline-first is great UX even when online
The point of a PWA is not only working with zero internet, it also makes your site load instantly on repeat visits (from cache) and stay usable on a flaky connection. Building offline-first means your users get a fast, resilient experience everywhere, not just on a plane. That reliability is why PWAs are worth the small extra setup.
Frequently asked questions
How can a website work offline?
By becoming a Progressive Web App with a service worker that caches its files on first visit, so the browser can serve the cached version with no internet.
How do I use a website offline?
On supported sites, use the Install icon in Chrome's address bar or Add to Home Screen on mobile. The installed PWA can then open and work offline.
What do I need to make a PWA?
HTTPS, a manifest file describing the app, and a service worker script that caches files and serves them when offline. Tools like Workbox help generate it.
What works offline in a PWA and what doesn't?
Cached pages, assets and local tools work offline. Live data, logins, syncing and fresh content still require an internet connection.
Comments
Post a Comment
If you have anything in mind, please let me know!