What are progressive web apps: Architecture & benefits explained

What are progressive web apps meaning?

Progressive Web Apps (PWA) is a web application that runs on a browser but has app-like experiences. It can operate as a web page on any browser or mobile app on any personal device. Many said PWA is a combination of rich functionalities of a website and a native app, such as working offline, push notifications, and auto-update.

Using different technology with many benefits, PWA has gained much attention recently. It is a web app technology that big tech companies such as Google, Microsoft, and Twitter have promoted since the early days.

Features of PWA

It’s crucial to know what makes progressive web applications tick before diving into the code:  

• Progressive: A progressive web app, by definition, can be accessed from any device and adapts and improves over time to make the most of the capabilities of the user’s device and browser.  
• Discoverable: PWA runs on a browser so search engines can index it. When compared to webpages, native apps are far less searchable.  
• Linkable : If the user saves or shares the web app’s URL, its state will be saved or restored when it is reaccessed.  
• Installable: A PWA can be added directly to the device’s home screen without downloading from an app store.   
• Fresh: When a user is online and a new piece of content is released, it should automatically appear in the app.  
• Safe : A progressive web app must be hosted over HTTPS to avoid man-in-the-middle attacks.
• App-like: A progressive web app uses the application shell design pattern to mimic the appearance and feel of a native app while requiring only occasional page reloads.  
• Connectivity-independent: It must function both online and offline (our favorite characteristic).
• Re-engageable: PWA uses features like push notifications to engage users longer than their mobile app counterparts.  
• 100% browser and device compatible, fully responsive  

Progressive web apps architecture & components explained

1. Web App Manifest 

The web app manifest is a JSON file that informs the browser about your Progressive Web Apps and how they should function when installed on the user’s desktop or mobile device. A typical manifest file comprises, among other things, the app name, the icons the app should use, and the URL that should be opened when the app is started.  

The web app manifest is an essential component of any PWA. These are all crucial early phases that contribute to forming users’ perceptions of your app, which is why you must do it properly.  

When a browser connects to a network for the first time, it searches the manifest file for resources, downloads them, and stores them locally. The browser then utilizes the local cache to render the web app while not connected to the internet. A web app manifest may help clients have a more dynamic mobile-friendly experience.

2. Service workers 

Service workers are a technological innovation that gives you command over your network requests, manages your alerts, and enables offline mode. They operate independently of any particular web page and run in the background of a browser to offer valuable functions.

There are three phases in a service worker’s life cycle: setup, activation, and registration. The service worker will register it, then install and activate it. Keep in mind that service workers are only compatible with HTTPS websites.  

Service workers’ primary function is to handle network requests. They may be used to store copies of static files, or “cache,” which can improve website load times and lower bandwidth needs. As a bonus, they may be used to alter incoming network requests or block them entirely.

3. Application Shell 

A website’s user interface cannot function without the foundational HTML, CSS, and JavaScript code known as an “application shell” in web development. Like a resume outline, it might help you start your application.  

To begin with, when a user launches Progressive Web Apps, the app’s shell is what loads. This guarantees a fast-loading UI, even when the user isn’t connected to the internet. Additionally, the application shell may be cached for rapid reloading on future visits.  

The application shell architecture is the best option when designing a dynamic app or website. If your site is static, you can skip the application shell. This technique is easier to implement since several existing JavaScript frameworks advocate separating your application logic from the content.

4. Transport Layer Security

PWAs are delivered using HTTPS, which encrypts the communication protocol using either Transport Layer Security (TLS) or Secure Sockets Layer (SSL).  

Transport Layer Security (TLS) is a cryptographic technology that provides network communications security. The protocol is extensively used in applications such as email, instant messaging, and voice-over IP, but its most apparent usage is safeguarding HTTPS.  

The TLS protocol’s primary goal is to offer security, including privacy (confidentiality), integrity, and authenticity between two or more interacting computer programs using cryptography, such as certificates. 

How do progressive web apps work?

Server-side Rendering (SSR) 

When a user launched a web-based application, the HTML that constituted the user interface and content was rendered on the device’s screen through server-side rendering (SSR). The browser requests the app’s server, which returns a file containing the data required to replicate the page on the user’s device locally.  

When the user navigates to another page or refreshes the current page, the process is repeated with a single monolith file received from the app’s server that contains the code for the page to be loaded.  

SSR enables customers to have fast initial renderings, a stable progressive web apps architecture with well-established infrastructure, and compatibility for all browsers independent of JavaScript functionality.  

However, it would help if you created a new document object model (DOM) for each user navigation. The round-trip request to your web server causes the rendering to be delayed.

Client-side Rendering (CSR) 

In CSR, the browser sends the first request to a content delivery network (CDN) rather than a server, which sends a base’wrapper’ containing all web page’s static HTML, CSS, and supporting file components. The browser then caches these items before making API queries through AJAX to get dynamic content JavaScript content rendered on the browser utilizing DOM processing.  

CSR’s initial page load time is longer than in SSR because more JavaScript must be downloaded and processed. A second HTTP request is required to load the material, followed by additional JavaScript to build the template. Even though the original JavaScript is cached, it must still be processed, and the second request cannot be made until the page has been loaded. 

What are the progressive web apps benefits?

Bookmarkable 

The user has the option of bookmarking the page. It implies they have it kept in storage and can retrieve it anytime. Consequently, customers are more likely to return to a specific app page and purchase your stuff.

Installation in a Flash 

PWAs, unlike traditional mobile applications, do not need a complex and lengthy installation method, which significantly improves the client experience.  

They do not need to visit Google Play or App Store. You can find the website on a browser first, then pin them right on your home screen.

Low development costs

You can reuse PWA’s source code for native app development in the future. Which in turn saves money and time for businesses.

Improved performance 

The ability of PWAs to cache and deliver pictures, text, and other material allows the app to behave like an efficient site and significantly boosts the app’s operating performance. Along with speed, flawless presentation is another factor that influences user experience and, as a result, conversion rates.

Push notification  

PWAs, like native mobile applications, have full access to device-based capabilities like push notifications. This skill may be used in various ways, allowing businesses to use content advertising effectively.

Offline process is simple 

PWAs are more suited than webpages because of their capacity to operate offline or in local networks. Inbuilt service workers unavoidably store major progressive web apps’ content and functionality, eliminating the need to download and allowing users to use it effortlessly without an internet connection. 

Progressive web apps disadvantage

As previously said, there are significant advantages for businesses to convert to PWAs, but there are also negatives to consider. Their disadvantages are closely related to their benefits:

Limited functionality and higher battery consumption

Despite their forward-thinking nature, they are still web applications. PWAs cannot offer native-app features like fingerprint scanning, proximity sensors, NFC, Bluetooth, geofencing, inter-app messaging, and extensive camera controls without access to device hardware. While distributing apps through URL is handy, it requires a connection, which depletes a device’s battery quicker than a native app. They are not as battery-efficient as web applications developed in native languages such as Swift or Kotlin since they are written in JavaScript.

Loss of search traffic 

We previously said that app store presence removes multiple steps users must complete before starting an app, reducing installation friction. Mobile site traffic may be sent to an app store to show off the app to consumers, while not being in an app store might result in traffic loss.

Problems with legacy devices 

PWAs have emerged for a few years, thus, it should come as no surprise that older mobile devices with outdated web browsers need to handle them properly.

Challenging to index for SEO 

Even though PWA is fast-loading with great user experiences that match the standard SEO requirements, its architecture can be complicated for search engines to crawl and index the content. So, PWA is not directly SEO-friendly. However, the user experience can be an advantage in the long run.

Who should use progressive web apps?

If you’ve already had a certain number of users and want to enhance the engagement.

PWA for start-ups and small businesses seem abundant. People have never heard of your brands, so what will make them find and pin your PWA?  

Secondly, PWA is only partially SEO-friendly. Yet, companies need to build the brand on search engines in the first stage. On the other hand, PWAs are all about user engagement. Giving your existing users a more convenient platform is an ideal strategy for an investment.  

• PWA is suitable for feature-rich websites such as eCommerce, social media, booking sites, entertainment sites, or productivity sites.  

• If you work in a sector that depends substantially on mobile traffic. 

You may benefit from higher retention and engagement rates since your customers do not need to download an app.  

People who depend on wireless networks and mobile connections are likelier to favor websites and applications that use less data and are at least partially functional offline. And PWAs have everything. 

Successful examples of PWA

Google thinks progressive web apps development is the future of software. AliExpress has improved new user conversion by 104% and average session length by 74% using PWA, according to Google.  

Twitter, Instagram, Telegram, Pinterest, and Tinder all employ PWAs and gain tremendous success. Twitter created the Twitter Lite PWA to boost engagement and minimize data use for its 328 million monthly users. The app launched in May 2017. Since over 80% of platform visitors utilize mobile devices, this move was timely. Twitter Lite shares tweets rapidly, requires less than 3% of device storage, and uses up to 70% less data.  

Meanwhile, The Washington Post’s is another popular example of progressive web app that also leverages AMP technology. They reduced page load time by 88% (400 milliseconds) compared to the mobile web. Mobile searchers returning within seven days increased by 23%.  

What is progressive web app development?

Progressive Web App Development is the process of creating a PWA that includes many steps, from researching, planning, designing, prototyping, coding, testing, and maintaining it. The development process can take a long time as PWA is very complex.

You will need to employ different frameworks, tech stacks and supported tools to do it. Future enhancement, upgrades or daily bug fixings are also considered a step in PWA development. The final goal of the development is to create a robust and seamless PWA for businesses and users.

What are the frameworks for PWA?

10 Best To Use Progressive Web Apps Frameworks: 

• React is a JS front-end toolkit introduced by Facebook in 2013 that has since become one of the most popular tools for designing web applications. 
• AngularJS is a modular framework that may be used with projects created with other technologies. 
• Ionic Framework is a free and open-source UI toolkit that allows you to create native-looking mobile apps that function seamlessly on iOS, Android, and other platforms. 
• Vue is designed from the bottom up to be progressively flexible, and it can swiftly scale between a library and a framework based on the user’s demands. 
• Svelte assemble HTML templates to build one-of-a-kind code that manipulates the Document Object Model. 
• Polymer is an open-source JavaScript toolkit for building web applications utilizing Web Components. 
• PWABuilder is a Microsoft application that turns websites into progressive web apps with little to no coding. 
• Webpack is a static module bundler for JavaScript application packaging. 
• Lighthouse is an open-source tool developed by Google that can be used through Chrome DevTools to audit web applications and PWAs automatically. 
• Magento PWA Studio is a tool for developing progressive web applications on the Magento eCommerce platform. 

Synodus‘s also review these frameworks for Progressive Web Apps in detail!

FAQ about progressives web apps

Wrapping up

Progressive web applications still have much potential, as top brands have leveraged this technology in recent years. However, its disadvantages and requirements make small businesses hesitate to use PWA. A progressive web app may be worth the effort because of its numerous benefits. Yet, you still need to consider your users and resources before using it.