What Is a PWA? How It Works, Benefits, and the Difference from Apps, Explained Simply

Now that smartphone use has become the norm, the "PWA" that lets you use a website like an app is drawing attention. Major services such as X (formerly Twitter) and YouTube have also adopted it, but surprisingly few people can accurately explain "what a PWA is" and "how it differs from a native app." This article clearly explains, for beginners, everything from how PWAs work to their benefits, the difference from native apps, and points to note.

What Is a PWA?

PWA stands for "Progressive Web Apps," a general term for web technology that gives a normal website app-like functions and usability. Built with standard web technologies—HTML, CSS, and JavaScript—it is characterized by providing performance and user experience (UX) close to a native app, even though it is accessed via a browser.

A website that has adopted a PWA becomes able to do things that were previously only possible with apps, such as adding an icon to the home screen, working offline, and sending push notifications. In other words, a PWA can be said to combine the strengths of both a website's "ease of attracting customers" and an app's "ease of use."

How PWAs Work | Two Core Technologies

PWAs can achieve app-like functions mainly thanks to two technical elements.

• Service Worker: A script that runs behind the scenes of a web page. By caching (temporarily storing) content, it enables offline display and receives push notifications. It also contributes to faster display speed.
• Web App Manifest: A configuration file that defines the app's name, icon, display mode, and so on. This makes it possible to add the website to the home screen and launch it like a native app.

By using these two technologies in an HTTPS environment that encrypts communication, a safe and highly reliable app experience is realized. HTTPS is also an operating requirement for PWAs, and it gives users a sense of security on the security front as well.

The Difference Between a PWA and a Native App

Indispensable to understanding PWAs is the difference from a "native app." A native app is the so-called typical "app" that you install and use from an app store such as the App Store or Google Play. The main differences between the two are as follows.

How to Obtain It (Installation)

The biggest difference is the installation method. A native app requires multiple steps in the app store—"search → download → install"—but a PWA can be added to the home screen with one tap from a button or pop-up on the website. This ease lowers the psychological hurdle of installation and leads to acquiring new users.

Development Cost

Because native apps differ in development language and environment between iOS and Android, in principle separate development is needed per OS. A PWA, being a website, can be developed with common web technologies without having to be conscious of OS differences. As a result, development effort and cost can be greatly reduced.

Updates

Native apps require store review (1–3 days on average) every time they're updated, but with a PWA, just updating the server side instantly reflects the latest version to all users. Being able to deliver bug fixes and new features speedily is a major operational advantage.

Relationship with Search Engines (SEO)

Native apps are only searched within the app store, but a PWA is indexed by search engines such as Google as a normal website. Therefore, being able to acquire new users from search results and receive the benefits of SEO is also a major difference.

PWAs and native apps are not an opposing "which is superior" relationship; it's appropriate to view them as something to use selectively, leveraging each one's strengths.

Five Benefits of Adopting a PWA

Building on the differences so far, let's organize the concrete benefits of adopting a PWA.

1. Reduces development and operating costs: It can support multiple OSes with one source, and store applications and reviews are unnecessary, so costs from development to operation can be cut.
2. Easy installation makes it easy to acquire users: It can be adopted with one tap without going through a store, preventing drop-off.
3. Provides SEO benefits: It is displayed in search results as a web page, lowering user acquisition costs through organic traffic.
4. Encourages return visits with push notifications: It can deliver new information and campaigns even to users who don't have the app open, raising engagement.
5. Fast display that doesn't strain storage: Cache use enables fast display, and device storage usage is also less than with a native app.

Since improving page display speed directly leads to improving Core Web Vitals, Google's evaluation metric, a strength of PWAs is being able to raise results on both the SEO and UX fronts.

Points to Note When Adopting a PWA

While there are many benefits, PWAs also have points to keep in mind before adoption.

• Some device functions are limited: For uses that fully utilize device functions, such as advanced camera control or Bluetooth integration, it may not match a native app.
• Support status differs by OS: The functions available can differ between iOS and Android, and prior checking is important especially in the Japanese market, where there are many iOS users.
• Offline operation is not all-purpose: Depending on the specification, not all functions are necessarily usable offline, so caution about the gap with user expectations is needed.
• The way to add to the home screen isn't well known: Because the access method differs from a native app, guidance (explanation) to users may be necessary.

Cases Where Adopting a PWA Is Suitable

PWAs are especially effective for services used repeatedly, like EC sites and media sites; when native app development costs don't fit the budget; when you want to add an app-like experience to an existing website; and when you want to strengthen touchpoints with users through push notifications.

Conversely, for services where full use of device functions is essential, a native app is more suitable. An approach of starting small with a PWA first while looking ahead to a future native app is also effective.

Conclusion

A PWA (Progressive Web Apps) is technology that gives a website native-app-like functions, achieving offline operation, push notifications, home screen addition, and more through the two core technologies of Service Worker and Web App Manifest. Compared with native apps, its major strengths are easy installation, reduced development costs, and SEO benefits. On the other hand, caution is needed regarding the limits on device functions. After determining whether your service needs an app-like experience, consider adopting a PWA as a strong option when you want to provide an app experience while keeping costs down.