Progressive Web Apps are web applications that take advantage of modern technologies to deliver engaging user experiences on desktop and mobile devices.
From a User Experience point of view, and as defined by Google, a progressive web app (or PWA) is a website that is:
Reliable - loads instantly
Fast - responds quickly to user interactions
Engaging - feels like a natural app on the device
Benefits of PWA
PWAs offer a better user experience, they work reliably and perform better.
This presents many benefits, including:
Better ranking in Search Engines
Main technical requirements for a website to be qualified as a Progressive Web App:
Runs under HTTPS
Includes a Web App Manifest
HTTPS (Hypertext transfer protocol secure) is the secure version of HTTP, which is the primary protocol used to send data between a web browser and a website. HTTPS is encrypted in order to increase security of data transfer.
E-commerce websites run under HTTPS because the security provided by it is a requirement to process transactions. In the world of PWAs, even content websites should run under HTTPS.
The web app manifest is a simple JSON file that provides information to the browser about:
How it should behaved when "installed" on the user’s device
Manifest file example
"name": "Hello World",
A service worker is a type of web worker with the following characteristics:
Runs separately from the main browser thread
Intercepts network requests, cache and retrieve resources from cache
Delivers push messages