WebAssembly will push PWAs to a whole new level

The evolution of application development has been shaped by a persistent tension between the reach of the web and the performance of native platforms. Progressive Web Apps (PWAs) and WebAssembly (WASM) represent two complementary technologies that are reshaping this landscape, bringing web applications closer to native performance and capability than ever before.

Progressive Web Apps emerged as a concept championed by Google starting in 2015. A PWA is a web application that uses modern browser APIs to deliver an app-like experience. The key technologies underpinning PWAs include Service Workers (background scripts that enable offline functionality and push notifications), the Web App Manifest (a JSON file that defines how the app appears when installed on a device), and HTTPS (required for security). Together, these technologies allow web apps to be installed on a user's home screen, work offline, send push notifications, and load instantly.

The advantages of PWAs over traditional native apps are significant. A single codebase works across all platforms -- desktop, mobile, and tablet -- regardless of operating system. There is no need to go through app store approval processes, freeing developers from the gatekeeping and revenue extraction of dominant app store operators. Updates are deployed instantly through the web, without requiring users to download new versions. PWAs are also discoverable through search engines, lowering the barrier to user acquisition compared to native apps buried in app store search results.

However, PWAs have historically faced limitations compared to native applications. JavaScript, the traditional language of the web, cannot match the raw computational performance of native code compiled from C++, Rust, or Swift. Access to device APIs like Bluetooth, NFC, file system access, and advanced camera controls has been restricted in browsers. On iOS, Apple has been slow to adopt PWA features, limiting the experience for iPhone and iPad users, though support has gradually improved.

WebAssembly addresses the performance gap directly. WASM is a binary instruction format that runs in the browser at near-native speed. It allows developers to write performance-critical code in languages like C++, Rust, Go, or C# and compile it to a format that browsers execute efficiently alongside JavaScript. This opens the door for computationally intensive applications -- image and video processing, 3D rendering, scientific simulation, game engines, and cryptographic operations -- to run entirely in the browser without plugins or native installations. Beyond the browser, the WebAssembly System Interface (WASI) extends WASM to server-side and edge computing environments, enabling portable, sandboxed execution of code across diverse platforms.

The combination of PWA and WASM is particularly powerful. A PWA provides the distribution model -- installable from the web, working offline, cross-platform -- while WASM provides the performance backbone for demanding workloads. Applications like Figma (the collaborative design tool), AutoCAD Web, and Google Earth demonstrate that complex, performance-sensitive applications can be delivered effectively through the browser using these technologies.

Frameworks have emerged to make this combination more accessible to developers. Blazor WebAssembly, from Microsoft, allows C# developers to build interactive web applications that run entirely in the browser via WASM. Yew and Leptos provide similar capabilities for Rust developers. These frameworks compile to WASM and provide component-based UI development models familiar to anyone who has used React, Angular, or Vue.

The native development ecosystem has also evolved in parallel. Swift and SwiftUI dominate iOS development, while Kotlin and Jetpack Compose are the standard for Android. Cross-platform native frameworks like Flutter (using Dart) and React Native (using JavaScript) attempt to bridge the gap by allowing developers to write code once and deploy to multiple native platforms. Kotlin Multiplatform (KMP), which reached stable status in 2023, has gained significant traction as a way to share business logic across iOS, Android, web, and desktop while keeping native UI on each platform.

The trend is clear: the boundaries between web and native development are dissolving. WebAssembly brings native-class performance to the browser, and the WASM Component Model promises to enable language-agnostic interoperability between modules. PWA APIs continue to expand, adding capabilities like file system access (via the File System Access API), Bluetooth (via Web Bluetooth), and USB access (via WebUSB). Meanwhile, native platforms are adopting web technologies -- Apple's App Clips and Google's Instant Apps blur the line between web and native experiences.

For developers and organizations choosing a technology strategy, the decision increasingly comes down to specific requirements rather than categorical differences. If you need the broadest reach with the lowest friction, PWAs with WASM provide a compelling solution. If you need deep integration with platform-specific features or the highest possible graphical performance, native development remains the stronger choice. In many cases, a hybrid approach -- using web technologies for reach and native components for platform-specific features -- offers the best of both worlds.

WASM, WebAssembly, HTML5, Kotlin, Scala, Java, Go