Progressive Web Apps

Progressive web apps combine apps and websites. They are useful from the very first visit because they behave exactly like a web page. That's because that is exactly what they are.

What are progressive web apps?

Some jargon

Service Worker A JavaScript file that runs separately from the main browser. It intercepts network requests, caches or retrieves resources from the cache. This is what can allow the progressive web app to run offline.

Manifest ### A JSON file that gives the developer the ability to control how your app appears to the user. It can set the icon, show something to the user while files are downloaded or restored from cache.


Traditional apps need to be built specifically for Apple iOS, Android and Windows devices. That can mean a lot of coding and maintaining of code. This is the reason apps can cost tens of thousands of dollars to build.

Progressive web apps don't require any download from app stores. They rely on native web sites. Build it once and let it run on multiple platforms.

Some websites could benefit from progressive web apps. Imagine have an app that is built in as part of your website.


There is currently one huge disadvantage. Progressive web apps are not currently supported by Apple Safari. Safari dominates phones and tablets. Around two thirds of European and North American phones and tablets use Safari. In Australia, it is close to 80%. Safaris is less dominant in Asia and Africa, where numbers are in the 40's.

The table below gives a breakdown on the 2 browsers Safari vs Chrome. It is worth noting that Safari doesn't support service workers. No matter where you are, that is a large slice of the market.

Safari vs Chrome on phones and tablets from Feb 2017 to Feb 2018

Safari Chrome
Asia Phones 49.86% 9.55%
Asia Tablets 41.28% 37.41%
Australia Phones 51.95% 35.4%
Australia Tablets 80.43% 14.6%
Europe Phones 51.95% 35.4%
Europe Tablets 62.47% 24.87%
Worldwide Phones 18.55% 51.66%
Worldwide Tablets 59.21% 24.15%



There is support for service workers in current versions of: Chrome (v45+), Firefox (v44+), Opera (v32+) UC Browser for Android (v11.8+) and Samsung Internet (v4+).

Currently, service workers are not supported by Internet Explorer, Edge or Safari. The good news is that support is coming. The next version of Edge is expected to support service workers.

Microsoft have expressed a desire to have progressive web apps in their store in the near future.

Apple are also making encouraging overtures about support in future versions. They haven't given a definite timeframe yet, but I doubt they will want to be left behind.

I think progressive web apps have got a good future. They could serve a complementary role to websites as well as enhancing them.

Progressive web apps combine the best apps and websites. They offer a viable way to integrate a website and an app.

Posted in Technology on Mar 26, 2018