What is WebAssembly? An introduction to Wasm

I’ve built web applications for over a decade, and JavaScript has been my trusty tool. However, as web apps grew more complex and performance-critical, I started feeling some limitations. Fortunately, I discovered WebAssembly, aka Wasm, a game-changer in my line of expertise. It allowed me to compile code written in languages like C++, Rust, or Go into a format browsers can understand. This opened a world of possibilities, enabling me to build web applications that are faster, more efficient, and more secure.

Beyond the browser, Wasm is revolutionizing server-side development, especially when paired with Kubernetes. In this blog series on WebAssembly, I’ll explore how it reshapes the future of web development and empowers us to build faster, more efficient, and secure applications.

What is WebAssembly?

WebAssembly is a low-level binary instruction format that can be run directly by modern web browsers, offering high-performance execution. It’s designed to be a low-level assembly-like language, making it a target for compilation from higher-level languages such as C++, Rust, and C#. This enables developers to write performance-critical code in these languages and run it directly in the browser alongside JavaScript. Wasm’s binary format is compact, resulting in smaller application bundles. It’s also designed to be secure and portable, allowing it to run in various environments, including browsers and server-side runtimes.

By leveraging Wasm, I can now create more complex and demanding web applications that I previously found impractical with JavaScript alone. This has opened many new possibilities for building high-performance, cross-platform applications that I can now deploy to the web, cloud, or edge devices. But was it always as powerful as it is today? Certainly not. It has come a long way since its inception. Let’s look at the evolution of Wasm.

Timeline of WebAssembly’s evolution

Why is WebAssembly essential?

WebAssembly has gained popularity because it has become increasingly important in day-to-day application development. Let me give you a gist of WebAssembly’s benefits.

For a long time, JavaScript has been the primary language that runs within the virtual machine, and it has worked quite well for that purpose. However, the increasing complexity of modern web applications has highlighted a significant challenge with JavaScript — performance bottlenecks. When running resource-intensive apps, such as 3D games, virtual reality and augmented reality, and video editing, we see JavaScript can’t deliver near-native performance. When coupled with the significant computational cost of downloading, parsing, and compiling large JavaScript-based applications, the performance problem becomes increasingly critical.

Although WebAssembly is a completely different language than JavaScript, it’s intended not to replace JavaScript but to run alongside it. This method enables developers to harness the advantages of both technologies in their applications. And, unlike JavaScript, since WebAssembly is a low-level, assembly-like language with a compact binary format, it makes it possible for WebAssembly to deliver near-native performance.

What are the benefits of WebAssembly?

While this can be a separate topic, I want to highlight the top four WebAssembly benefits I have seen in my experience (not in any particular order).

• Performance: This is a no-brainer. With near-native speed, WASM code executes significantly faster than JavaScript, especially (read more..)