Sign up


3 Best Practices for Developing High-Performance Progressive Web Apps (PWA)

Angela Stringfellow

Last updated on

Progressive web apps (PWAs) allow developers to build web pages that mimic the native app experience without breaking the budget. They’re a smart way to build applications by combining web and mobile app features, giving users what they need without overwhelming your development team.

So, why are PWAs gaining so much traction? For starters, they offer the sleekness and speed of a mobile app with the reach and accessibility of the web.

This means you can engage more users, streamline their experience, and watch those conversion rates soar without the usual complexity of native app development. However, it’s crucial to follow best practices for developing high-performance progressive web apps.

That includes optimizing your assets, leveraging caching with service workers, and setting up progressive web enhancement. It's all about delivering a seamless, app-like experience that keeps users coming back for more.

PWAs are an excellent compromise, but the right approach will help you get even more out of this unique online experience. Check out this guide to craft PWAs that are both functional and impressively responsive.

In this article:

1. Optimize Assets

Developers working on asset optimization
Image by Desola Lanre-Ologun from Unsplash

When it comes to building lightning-fast progressive web apps, the devil is truly in the details—or, in this case, the assets. The more optimized your assets, the faster and smoother your PWA will run on iOS, Android, and other platforms.

Optimize assets by:

  • Compressing images: You can significantly speed up load times with tools like TinyPNG or ImageOptim that reduce file sizes without losing quality.
  • Minifying code: Strip out unnecessary characters from your code to make your scripts and stylesheets nice and lean.
  • Switching to modern formats: Embrace formats like WebP for images and ES6 for JavaScript. They offer better compression and more features compared to their predecessors.
  • Setting up lazy load: Instead of loading all images simultaneously, lazy loading only loads images when they enter the user’s viewport, reducing load times and saving bandwidth.

2. Leverage Caching With Service Workers

Person touching cache and development icons graphic overlay
Image by Panchenko Vladimir from Shutterstock

Transforming your web app into a PWA isn't just about sprucing up the user interface; it's also about making it resilient and reliable, regardless of network conditions. This is where service workers come into play, acting as a conduit between your app and the network.

Service workers are scripts that run in the background of a browser, separate from a web page. You can supercharge your PWA with service workers that allow offline capabilities and improve network resilience. Service workers can also handle caching, which speeds up the user experience and overall PWA performance.

Follow these simple caching rules to speed things up:

  • Check the cache first: This setup is when you check the cache first and use resources if they’re available, only reaching out to the network if the cache doesn’t have the file. Cache-first is perfect for assets that don’t change often, like CSS or images.
  • Access the network first: With this approach, you fetch the freshest content from the network first. If the network isn’t available, the PWA displays the cached version. It’s useful for content that updates frequently, ensuring users always see the latest posts or comments when possible.
  • Stale-while-revalidate: This combined approach serves resources immediately from the cache for quick loading while fetching newer versions from the network. The user will see the updated content the next time they visit.

3. Set up Progressive Enhancement

JavaScript developer
Image by UnderhilStudio from Shutterstock

Progressive enhancement is a PWA design strategy that boosts usability. You start with a foundation that works for everyone and build up to more advanced features for users with more capable browsers. This approach ensures your PWA is functional across various devices, helping you reach a wider audience.

First, start with the app’s core functionality. Design your app's core features to operate even in the most rudimentary web browsers or under poor network conditions. For example, that might mean using text-based, functional navigation without CSS or JavaScript.

From there, you can jazz up your app for users with more advanced browser capabilities. For example, you could add richer layered experiences, like advanced animations or interaction effects, that add to the experience without disrupting the core functionality for users on less capable devices.

Design a Cutting-Edge PWA Users Love

Developers discussing PWA development
Photo by John Schnobirch from Unsplash

Progressive web apps give users access to resources without downloading yet another app. For brands and developers, they give you a direct line of communication with users without spending more time and money building a native app. It’s a win-win!

Minor changes to your PWA can have tremendous results for the user experience. Optimize assets, use caching, and follow a progressive enhancement strategy to build a seamless experience.

Setting up notifications is a good idea if you want folks to engage with your PWA regularly. You don’t have to build a notification system from scratch, either. MagicBell is an all-in-one messaging inbox that sends push notifications specifically for PWAs. Give MagicBell a test drive: Create your free account now.

Ready to launch your notifications? Check out to demo your web push notifications on all platforms, including iOS.

Frequently Asked Questions

Are progressive web apps secure?

They can be, although it depends on their design. PWAs must use HTTPS to safeguard all data, keeping it encrypted and secure at all times. Some brands also create Content Security Policies (CSPs) to address security vulnerabilities.

Does a PWA work on all browsers?

Progressive web apps work on most modern browsers. Any browser that supports service workers and cache APIs should support PWAs. However, every browser handles features differently, so test your PWA across multiple browsers before launching it.

How do I handle data storage in a PWA?

PWAs handle data using IndexedDB, cache API, and local storage. There are plenty of ways to manage data storage, so the best option depends on the data size and how you need to interact with it.