May 21, 2020

What Are Progressive Web Apps?

Progressive Web Applications
Mobile Application Testing

Progressive web apps, also known as PWAs, are popular web applications that are adopted by many leading brands. But there can be challenges in testing them. Here, we answer what are progressive web apps? And we break down considerations and challenges in testing them.

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What Are Progressive Web Apps?

Progressive web apps are types of web applications that are regular webpages or websites. But they can appear to the user like traditional apps or native mobile apps.

Progressive web apps combine features offered by modern browsers with the benefits of a mobile experience.

Progressive web apps are:

  • Progressive: they work for every user.
  • Responsive: they fit any form factor.
  • Connective: they are independent of connectivity and support offline caching.
  • App-like: they feel like apps.
  • Safe: served via HTTPS.
  • Search-friendly: they can be found using search engines.
  • Re-engageable: they support push notifications.
  • Linkable: they don’t require complex installation (or store access).
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Progressive Web Apps vs. Native Apps vs. Web Apps: What’s the Difference?

So what’s the difference between web apps, progressive web apps, and native apps?

The biggest difference is that a progressive web app is a boosted web app. It acts like a native app but it operates in a browser — so you don’t need to download an app from the App Store or Google Play.

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Why Use Progressive Web Apps?

Progressive web apps are more efficient and economical than native apps.

If you develop native or hybrid apps, you need separate teams for each application type. For example, for Android, you need developers that are strong in Java. For iOS, you need Swift or Objective-C developers, depending on the iOS version. If you have a separate website, you need JavaScript developers.

That means you need separate resources — and sometimes even separate teams — just to develop the technology.

Plus, you have to go through the process of deploying the Apple App Store or Google Play any time you:

  • Make changes.
  • Add capabilities.
  • Want to support a new platform.
  • Want to push a new version.

This can result in delays in your schedule.

Progressive Web Apps Save Time

With progressive web apps, you get the same advantages of standard web applications. You can change anything on your website — backend or frontend — and push it live to production without relying on application store developers.

The mobile capabilities in a progressive web app are rich in functionality. For instance, a progressive web app has offline caching, so the user can still engage when not connected to the internet.


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How to Build Progressive Web Apps

A progressive application is built on top of any website that you have. It consists of two key components you’ll need your developers to implement.

1. Build It With Manifest.JSON

Manifest.JSON is a text file that profiles the entire website. It gives you the name, the link, and the landing homepage of the website when you create it as an installable app on your mobile device.

2. Implement Service Worker

Service worker is the most important implementation behind the progressive website. It's the brains behind the website.

Service worker allows you to implement:

  • All the push notifications.
  • The offline caching strategy.
  • Working with sensors.
  • Accessing all the OS specific abilities, like the contact list and storage.

3. Decide if You Should Use a PWA Builder or Build It Yourself

You can build a progressive web app using a PWA builder (there are many of these available). Or if you have the development resources, you can build it yourself.

So, there are many advantages of building a progressive web app. But what does testing look like?

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Testing Challenges For Progressive Web Apps

Testing progressive web apps can be challenging. Here are some of the top challenges.

Young and Growing

Progressive web apps are young and growing compared to standard websites. This can make them more difficult to test.


The architecture of progressive web apps is not as simple as responsive web design sites. Your developers need to understand the logic behind working with service workers and managing events, states, caching, and more.


Your frontend developers will need to catch up with this technology to be successful.

Caching Architecture

The caching is very sophisticated in progressive web apps. And there are differences between iOS and Android. For example, iOS limits the caching on an iOS device, but Android is a bit more free.

Limited Open Source Options

There aren't that many open source or third party integrations working with progressive web apps. It's growing, but it's not yet perfect. This can be another challenge when you’re building a website.

OS Updates

Maintaining OS updates can be a challenge. You’ll want to make sure that you are keeping up with the market. You don’t want to cause any regression as a new smartphone or tablet operating system is introduced.

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Testing Tips For Progressive Web Apps

Consider the following progressive web app quality metrics for testing:

  • Starts fast, stays fast.
  • Works in any browser.
  • Responsive to any screen size.
  • Provides a custom offline page.
  • Is installable.
  • Provides an offline experience.
  • Is fully accessible.
  • Can be discovered through search.
  • Works with any input type.
  • Provides context for permissions requests.
  • Follows best practices for healthy code.
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Progressive Web Apps: A Test Plan

Here’s a test plan for responsive web apps. The first six steps come from a test plan for responsive web apps. The last six steps are specific to progressive web apps.

  1. Choose the right platforms.
  2. Assure visual web pages across platforms.
  3. Functionality of navigation flows and menus.
  4. Client-side performance testing.
  5. Test accessibility for mobile and web.
  6. Test environment conditions (networks, sensors).
  7. Validate PWA manifesto.
  8. Validate PWA service workers.
  9. Validate PWA specific capabilities.
  10. Properly test across platforms.
  11. Test automation and object identification strategy.
  12. Google’s PWA checklist compliance.
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Build Better Progressive Web Apps With Perfecto

When building progressive web apps, you need to consider testing. And progressive web app testing is better with Perfecto.

For instance, you can use a framework like Appium that supports testing of progressive web apps. And Appium integrates with Perfecto.

So you can use Perfecto with Appium to test progressive web apps and:

  • Scale testing across platforms.
  • Ensure security.
  • Support advanced automation scenarios.
  • Find and fix bugs faster.
  • Integrate solutions that fit your processes and tool stack.

See for yourself how Perfecto makes progressive web app testing better. Get started today with a free 14-day trial.



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