PWA apps (progressive web apps) — what they are and how they’re built

According to Google, users left sites that took longer than 3 seconds to load in 53% of cases. This is not just a number, but a signal for all companies: speed and ease of access are becoming critically important for attracting and retaining customers.

In these conditions, PWA — progressive web applications — have become a real breakthrough. They make it possible to build solutions that combine the advantages of native apps and websites: instant loading, offline mode, push notifications, and cross-platform support. Companies such as Starbucks and Twitter already use PWA to increase user engagement and improve conversions.

Why is this technology in such high demand? First, it helps businesses reduce the cost of building apps for different platforms. Second, it improves the user experience, which matters in an environment of growing competition.

In this article, we will cover:

• What PWA are and why they are becoming more popular.
• What benefits they bring to your business.
• How PWA are built: key stages and technologies.

Read on to learn why PWA are not just a trend, but a necessity for businesses that want to maintain leadership in the digital age.

1. What is PWA?

PWA (Progressive Web Application), or a progressive web application, is a new standard in web development that combines the best qualities of websites and native apps. This approach makes it possible to build applications that run in the browser while delivering a user experience comparable to full-featured mobile apps.

Key characteristics of PWA

1. Installation on a device
   Users can add progressive web applications to the home screen of a smartphone or tablet without needing to go to the App Store or Google Play. This makes installation quick and convenient, lowering barriers to engagement.
2. Offline mode
   PWA use data caching, so core app features are available even without an internet connection. For example, a user can keep filling out a form or viewing previously loaded content.
3. Push notifications
   Progressive web applications support push notifications, which helps businesses engage users and keep their attention. This feature is especially useful for online stores and services that provide personalized offers.
4. Cross-platform support
   PWA work on any device and any operating system, providing the same user experience on mobile devices, tablets, and desktop computers.
5. High performance
   Progressive web applications load faster thanks to optimizations using service workers. This helps minimize delays, which is especially important for users with slow internet.

How does PWA work?

• Service workers
  This is a technology that acts as an intermediary between the browser and the server. Service workers cache data, allowing the app to work offline, load pages quickly, and stay stable.
• Manifest file
  This is a JSON document that defines how the app will look and work on the user's device. It contains information about the app name, icons, interface colors, and other parameters.
• HTTPS
  For security, PWA must operate over the secure HTTPS protocol. This eliminates the risk of data leaks and makes the app safe for users.

How is PWA different from native apps?

Why is PWA the future?

PWA combines everything users need: convenience, speed, and functionality. For businesses, this solution makes it possible to reach a broad audience without significant development investment. In the following sections, we’ll explain how PWAs are built and what technologies are used to develop them.

2. Key advantages of PWA

Progressive web apps have become popular thanks to their unique set of advantages that make them useful for both users and businesses. Let’s look at why PWA is becoming the best option for today’s digital world.

1. Faster load times and better performance

PWAs load significantly faster than traditional websites thanks to efficient caching and the use of service workers. Fast page loads deliver a better user experience, especially in regions with slow internet connections.

2. Offline mode

PWAs store cached data, allowing users to keep using the app even without an internet connection. For example, an online store can show previously viewed products, and a news site can show articles loaded during the last connection.

3. Increased user engagement

With push notifications, PWA helps retain users and engage them in active interaction. Notifications can be used to remind users about discounts, updates, or personalized offers.

4. Versatility and cross-platform support

One app works on all devices: smartphones, tablets, and desktop computers. This simplifies development and lets businesses reach a broad audience faster.

5. Savings on development and maintenance

A PWA is built on a single codebase, which reduces costs compared to developing separate apps for iOS and Android. In addition, updates are deployed automatically, without requiring the user to download them.

6. Improved SEO and accessibility

Since a PWA functions like a web app, it is indexed by search engines, which has a positive effect on SEO. Fast loading and a high-quality user interface also improve search engine rankings.

7. Lower bounce rates and higher conversion

Progressive web apps provide an intuitive, fast experience, which reduces bounce rates. For example, after implementing a PWA, the AliExpress platform increased conversion by 104%, and Pinterest by 60%.

8. Easy installation

Users can add the app to their device’s home screen in just a couple of clicks through the browser. This lowers the installation barriers that exist with native apps (searching the app store, downloading, installing).

Who benefits from using a PWA?

PWA works well for a wide range of industries:

• E-commerce: Fast product loading, push notifications about discounts.
• News portals: Access to content without the internet.
• Delivery services: Offline functionality for placing orders.
• Educational platforms: The ability to learn without a network connection.

Real-world examples of successful implementation

• Starbucks: PWA enabled users to place orders offline, which increased the number of orders from mobile users.
• Twitter Lite: The app became 70% lighter, ensuring fast performance even on 2G networks.
• Forbes: Reducing load time by 2–3 seconds led to a 43% increase in views.

These examples show that PWA is not just a convenient tool, but also a strong solution for achieving business goals. Next, we’ll look at how such apps are built.

3. How are PWAs built?

Building a progressive web app is a process that includes several development stages and the use of modern technologies. Let’s break down how PWAs are built, step by step.

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1. Planning and design

Any successful project starts with analysis:

• Target audience: Who will use the app, and what are their needs and devices?
• Features: What tasks should the PWA handle? For example, push notification support, offline operation, high performance.
• Business goals: Increasing conversions, improving the user experience, or reducing development costs.

At this stage, an interface prototype (UI/UX) is also created to ensure intuitive navigation.

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2. User interface (UI) development

Standard web technologies are used to build the interface:

• HTML for markup.
• CSS for styling.
• JavaScript for dynamic application behavior.

Modern frameworks such as React, Angular, or Vue.js make it possible to speed up development and make the application more stable and scalable.

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3. Implementing service workers

Service workers are scripts that run in the browser background and let a PWA work without a constant connection to the server. Their main functions are:

1. Data caching:
   Service workers let you store key application elements such as CSS, JavaScript, or images in the device’s local storage. This speeds up page loads on repeat visits.
2. Background sync:
   Users can perform actions offline (for example, filling out forms or ordering products), and the service worker syncs the data with the server as soon as the device connects to the internet.
3. Push notifications:
   Service workers manage sending notifications that help engage users and inform them about new offers.

The effectiveness of service workers can be illustrated with Twitter Lite data, where using service workers reduced load time to 3 seconds even on 2G networks.

An example of a simple service worker:

self.addEventListener('install', (event) => {
  event.waitUntil(
    caches.open('my-pwa-cache').then((cache) => {
      return cache.addAll(['/index.html', '/styles.css', '/script.js']);
    })
  );
});

4. Configuring the manifest file

The manifest file is a JSON file that contains information about the PWA:

• The app name.
• Icons to display on the device screen.
• Color scheme.
• The URL to load.

An example of a manifest file:

{
  "name": "My Progressive Web App",
  "short_name": "MyPWA",
  "icons": [
    {
      "src": "icon-192x192.png",
      "sizes": "192x192",
      "type": "image/png"
    },
    {
      "src": "icon-512x512.png",
      "sizes": "512x512",
      "type": "image/png"
    }
  ],
  "start_url": "/index.html",
  "background_color": "#ffffff",
  "display": "standalone",
  "theme_color": "#000000"
}

5. Ensuring security via HTTPS

All PWAs must run over HTTPS. This protects user data and ensures service workers function correctly.

Setting up HTTPS:

• Use SSL certificates (for example, from Let’s Encrypt).
• Set up automatic redirects from HTTP to HTTPS.

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6. Testing and optimization

At this stage, the following is checked:

• App performance (using Google Lighthouse).
• Correct operation of service workers and offline features.
• Compatibility with different devices and browsers.

Example of a Lighthouse report:

• Load speed: 95/100.
• SEO: 90/100.
• Reliability: 100/100.

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7. Publishing

Unlike native apps, PWAs don’t require listing in app stores. It’s enough to:

• Host the app on a web server.
• Provide access through a browser.

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8. Monitoring and updates

PWAs update automatically, which eliminates the need for any additional actions from the user. For a business, it’s important to track key metrics such as:

• Increased user engagement.
• Load speed.
• Number of installs.

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Building a PWA is a combination of solid planning, development, and testing. In the following sections, we’ll review tools that simplify the development process, as well as real examples of successful PWAs.

4. Core technologies and tools for PWA development

Building a progressive web app requires using a specific set of technologies and tools. They provide high performance, security, and a convenient development experience.

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1. Technologies for PWA development

PWA development uses standard web technologies enhanced with modern tools:

1. HTML5
   The primary markup language for creating the app’s structure.
2. CSS3
   Used for UI styling, responsive design, and animations.
3. JavaScript (ES6 and above)
   The main tool for interactivity, application logic, and server communication.
4. Service Workers API
   Provides caching and offline capabilities and improves performance.
5. Web App Manifest
   A JSON file that defines the app’s appearance and behavior parameters, such as the name, icons, and color scheme.
6. HTTPS
   A mandatory requirement for PWAs, ensuring data security.
7. Push API
   Enables push notifications to drive user engagement.

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2. Frameworks for PWA development

Frameworks simplify the development process by providing ready-made solutions:

• React
  A lightweight and fast framework, ideal for building PWAs. With the Workbox library, React integrates with service workers.
• Angular
  A framework from Google that provides powerful tools for developing and maintaining PWAs. Angular CLI simplifies configuration and adding service workers.
• Vue.js
  A compact and intuitive tool for building PWAs, especially convenient for small projects.

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3. Development and testing tools

These tools help speed up PWA development, testing, and optimization:

1. Lighthouse (Google)
   Tool for auditing PWA. Checks performance, accessibility, SEO, and compliance with PWA standards.
2. Workbox
   A library for managing caching and service workers. Simplifies offline mode and data updates.
3. Webpack
   Used to bundle JavaScript modules, CSS, and other resources, which helps optimize app loading.
4. DevTools (Chrome)
   Built-in tool for debugging service workers, cache, and other PWA features.
5. Firebase
   Platform for hosting, setting up push notifications, and managing a real-time database.

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4. Recommendations for implementing PWA

• Use progressive enhancement: start with basic functionality and gradually add capabilities.
• Monitor code quality: optimize JavaScript and CSS, reduce image size.
• Update the app regularly: PWA update automatically when service workers are configured correctly.

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5. Examples of using technologies

• Starbucks PWA: built in React using Workbox for caching.
• Twitter Lite: actively uses Web App Manifest and service workers.
• Pinterest: built on Angular with optimization through Lighthouse.

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Using modern technologies and tools makes PWA development accessible and efficient. In the next sections, we will look at real examples of successful PWA and break down how they help businesses achieve their goals.

5. Real-world PWA use cases

Progressive web apps (PWA) have already proven their effectiveness across various industries. Many large companies have implemented PWA and achieved impressive results: from increased user engagement to higher conversions. Let’s look at a few examples of successful use of this technology.

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Large companies

1. Starbucks: accessibility for everyone

• Task: Provide a convenient way to order coffee for users on any device, including regions with limited internet access.
• Solution: Starbucks developed a PWA that weighs less than 1 MB, significantly smaller compared to their native app. Users can order coffee even if the internet connection is temporarily unavailable.
• Result: The number of orders from mobile users increased, and the customer base grew thanks to the app’s availability under weak internet conditions.

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2. Twitter Lite: fast and efficient

• Goal: Provide users with a platform with fast access to content, especially in countries with slow internet connections.
• Solution: Twitter created a PWA called Twitter Lite that runs in the browser, takes up minimal memory, and loads instantly.
• Result: The app became 70% lighter, and the number of tweets grew by 75%. Bounce rate decreased by 20%.

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3. Pinterest: increasing engagement

• Goal: Overcome high bounce rates on mobile devices and improve the user experience.
• Solution: The company implemented a PWA by optimizing performance and adding offline functionality.
• Result: Conversion increased by 60%, and user engagement rose by 40%. The PWA made it possible to acquire new customers faster.

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4. AliExpress: global success

• Goal: Increase conversion on mobile devices, which accounted for most of the traffic.
• Solution: AliExpress implemented a PWA with a focus on loading speed and ease of use.
• Result: Conversion across all platforms increased by 104%, and the time users spent interacting with the app grew by 74%.

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5. Forbes: performance improvements

• Goal: Speed up news content loading and increase the time users spend on the site.
• Solution: Forbes developed a PWA that provides instant article loading and offline access to news.
• Result: Load time dropped to 0.8 seconds, which increased pageviews by 43%.

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6. Trivago: a leader among hotel search engines

• Goal: Provide fast access to hotel booking information for users across different devices.
• Solution: Trivago implemented a PWA that offers instant search and the ability to work offline.
• Result: Users started returning to the site more often, and interaction with the app increased by 150%.

Small and medium-sized businesses

PWA provides significant advantages not only to large companies, but also to small and medium-sized businesses. Here are a few examples of how this technology can be used:

1. Local shops and cafes:
   Small businesses can build a PWA to display menus, place orders, or book tables. For example, a local cafe in Spain implemented a PWA, which allowed customers to order food online and save the menu for offline access. This increased repeat orders by 30%.
2. Educational courses and trainers:
   Private tutors can use a PWA to provide materials to their students, available even without internet access. One example is a language-course platform that allowed students to download study materials and tests via a PWA.
3. Delivery services:
   For small delivery services, such as local bakeries or flower shops, a PWA can be an ideal solution. Users can place orders even in areas with poor internet, and delivery status notifications arrive in real time.
4. Event agencies:
   Event organizers can use a PWA to publish event schedules, sell tickets, and send notifications about upcoming events. This is convenient for users, who can save the app to the home screen and avoid searching for information online.

These examples show that a PWA can be adapted to any small-business needs, helping improve the customer experience, reduce development costs, and attract more users.

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Why do businesses choose PWA?

These examples confirm that implementing a PWA leads to the following results:

• Higher conversions: Speed and convenience attract more users.
• Lower costs: One app for all platforms reduces development and maintenance costs.
• Better user experience: Fast loading and offline access make the app convenient for users.

PWA is not just a trend, but a strategic solution for a business that aims to improve its performance and customer interaction. In the next section, we’ll discuss why your business, specifically, should implement this technology.

6. Why does your business need a PWA?

Integrating progressive web apps (PWA) is not just a move toward innovation, but a strategic approach that can significantly affect your business efficiency. Let’s look at why PWA will become a key tool for achieving your goals.

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1. Improving the user experience

Today’s customers value speed, convenience, and stability. A PWA provides:

• Instant loading: Users don’t like to wait — every second of delay reduces conversion.
• Intuitive interface: Simplicity and ease of use increase customer satisfaction.
• Offline access: Your services or content are available even when there’s no internet connection.

Example: If your online store uses a PWA, a customer can continue shopping even with a weak signal, and the data will update at the first connection.

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2. Lower development costs

Building and maintaining native apps for different platforms (iOS and Android) requires significant costs. PWA solves this problem:

• One version of the app works on all devices.
• Updates and improvements are rolled out centrally.

This is especially beneficial for small and mid-sized businesses, where every ruble invested must deliver maximum results.

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3. Higher customer engagement

PWA helps retain users and bring them back:

• Push notifications: Reminders about discounts, promotions, or new products drive repeat visits.
• Home screen icon: The app is always “in sight,” which increases the likelihood of interaction.

Example: The AliExpress online store increased conversion by 104% thanks to push notifications and offline access.

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4. Broader audience reach

PWA doesn’t require installation via the App Store or Google Play, which lowers barriers for new users:

• Installation takes just a couple of seconds.
• The app is available directly from the browser.

This matters for markets with low internet speeds or limited access to an app store.

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5. Improving SEO

Since a PWA is a web app, it’s indexed by search engines, unlike native apps. This gives your business additional advantages:

• Better visibility in Google.
• Increased organic traffic.

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6. Staying ahead of competitors

In a highly competitive environment, companies need to look for ways to stand out. A PWA helps:

• Roll out innovations faster.
• Create a memorable user experience.
• Shorten the customer journey from the first visit to purchase.

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7. Examples of industries where PWAs are already successful

• Ecommerce: Fast ordering, offline catalogs, personalized offers.
• Media and news: Instant article loading, saving content for offline reading.
• Delivery services: The ability to place orders even without a network connection.
• Education: Access to learning materials without the internet.

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8. Long-term benefits

• Lower marketing and advertising costs thanks to better user retention.
• Higher customer loyalty due to ease of use.
• Faster achievement of business goals.

7. Conclusion

Progressive web apps (PWA) aren’t just a tech novelty, but a real opportunity for businesses to reach a new level. They combine ease of use, high performance, and cost-effective development, giving users an experience comparable to native apps.

Key benefits of PWA for your business:

• Speed and convenience: Fast loading and offline operation make PWA an ideal solution for customers on any device and in any conditions.
• Accessibility: Easy installation through a browser lowers barriers for new users.
• Cost savings: Building one universal app is significantly cheaper than maintaining multiple native versions.
• SEO optimization: Unlike native apps, PWAs are indexed by search engines, increasing organic traffic.

Why start now?

The world is rapidly moving toward mobility and digitization. Consumers expect convenience and reliability, and competition requires adopting innovation. Companies that implement PWAs today gain not only a competitive advantage but also the ability to build long-term relationships with customers.

Your next steps:

1. Define your business’s key goals and the audience the PWA is being built for.
2. Reach out to a professional development team that will help deliver the project.
3. Track the results to make sure your investments are working for you.

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Don’t miss the chance to make your business more competitive! Contact the Amiscon experts to learn how PWA will help you increase conversions, improve the user experience, and reduce costs.