What is a progressive web app?

The founder and developer of progressive web apps are designer Frances Berriman and engineer Alex Russell. The recent survey report by Comscore suggests that 50% smartphone users in the USA do not download a single app a month. Progressive web apps are introduced to accomplish this issue.

As explained earlier, progressive web apps are going to give the experience of native apps on mobile web browsers such as Chrome, Opera.

Progressive web apps are hosted on user’s servers and can be updated without any need of issuing new updates to a play store or app store. These web apps have all the native-like capabilities such as offline working, background refresh, quick loading, push notifications, and installability.

How does progressive web apps work?

The core technology of progressive web apps is Service Worker. Service Workers is a technology behind progressive apps which is extremely powerful and robust. They enable the offline functionality, content caching, push notifications, background content updating.

Service Worker is a worker script which works behind the scenes that run in response to network requests, push notifications, connectivity changes, and more. A service worker acts as a proxy, or middleware for this kind of requests. These service workers are compelling and also very difficult to understand. With lots of great features, it can be immensely confusing for web app developers to understand the working of Service Workers.

These are just like any other JavaScript file where the developer needs to write code for different events like caching, content fetching, push notifications. Service Workers are currently available on Android with Chrome 50 and not on some major mobile browsers.

Another technology used is App Shell. App Shell is a design concept that enables the app shell to load first, and content later. Design and content are cached separately. It improves the performance and usability of the app.

Do you know what app manifest is? The fun part about any mobile app is that you can take it on the home screen to use it quickly whenever required. Just the way you create a shortcut for any software in your computer system. However, how to bring shortcut of any web app on the home screen? Chrome on Android has support for web apps to install on the home screen with the help of a native install banner.

To indicate that the progressive web app is installable as an app, developers write a manifest.json file, and this file is linked to the main HTML page. Android has immediately adapted with progressive web apps and started offering support. However, iOS is yet to welcome progressive web apps completely. As we know, due to security reasons, iOS has some strict rules and policies. Hence, it will take time.

Benefits of Progressive web Apps:

  • No load time- Progressive web applications are available instantly.
  • Responsive- The primary concern of all app developers and designers is to offer responsive apps on all devices such as mobile, desktop, laptop, tablet.
    Progressive web apps are equally responsive on all the devices.
  • Progressive- As the name suggests, these web apps are progressive. These are built with progressive enhancement and can work on any browser.
  • App shell mode- You can build progressive web apps on app shell technology and hence they deliver an app like feel to the users.
  • User engagement- With specific features like push notifications, progressive web apps are highly user engageable.
  • Size and Auto update- As discussed the average size of mobile apps is 30 MB to 200 MB. However, the progressive apps are within some KBs. Besides, due to Service Workers, these apps are updated automatically.
  • Works offline- There are some situations when an app is needed urgently, but the user does not have an internet connection. This problem is resolved in progressive web apps. Again the Service Workers are a saviour! They act as a network proxy. Whenever a page is requested, Service Workers tries to access that content from the cache.


The app development company that performs progressive web app development is sure going to reach a vast number of end users soon. Though the concept is slowly getting fame, active and top app development companies have already started working on it. Some favourite brands that do progressive web app development are Ola, Twitter, BookMyShow, Alibaba, OLX, Flipkart.