What are Progressive Web Apps

October 21st, 2018

For those who have not heard about progressive web applications, PWA’s are applications that run on browsers with more flexibility and user centric experience than a normal website. The progressive web apps has more capabilities than a normal website. It relies on single page application concept where the entire website is made as a single page and the content changes dynamically on that page.

The progressive web apps are introduced to remove the dependence on network, ensuring an instant and reliable experience for the user. The progressive web app can run as a normal mobile application on a mobile device. Even though there is no internet connectivity, the PWA’s can show you a pre-loaded content or store the requested network calls and sync the app whenever a network connection is established. This is done by a service worker which is written in JavaScript, which acts as a middle man between the application and the server.

The progressive web application resides on the client side and connects to a server for the data. The service worker stands between them requesting and responding on behalf of the application. The service worker also maintains a cache of the assets required by the application to reduce the load time and speed up the application.

Another advantage of progressive web apps is, it’s installable on a device. Whenever the ‘add to home screen’ button is pressed, the PWA get installed and it can work like a normal mobile application. The PWA’s also supports push notifications and background activities same as normal native mobile applications.

The initial load of a progressive web app can take time to load the application files and store it in cache, but the next launch won’t take more than 5 seconds to start up the application.

Below is a list of companies using PWA’s in their applications.

Infographics by henrylim96 reference (InsaneLab)