Web Assembly (abbreviated as Wasm) is a binary instruction format for a stack-based virtual machine. It is designed as a low-level language for compiling high-level languages such as C, C++, and Rust into a format that can be run in modern web browsers. It is a key technology for the future of the web, as it allows developers to write complex and high-performance applications that run natively in the browser.

One of the main advantages of Wasm is its performance. Because it is a low-level language that is compiled into a binary format, it can run much faster than JavaScript, the current language of the web. This is especially important for applications that require a lot of computational power, such as games, video editing, and scientific simulations. This improved performance can lead to a better user experience, as web applications can run more smoothly and efficiently.

You might ask, how much faster is WebAssembly compared to JavaScript? To find out, you can use this useful app built by originjs.org to run tests directly in your browser

Even though companies such as Figma reduced their loading time by 3x using WebAssembly, JavaScript can still sometimes be faster than WASM

This is especially the case when invoking web APIs from WebAssembly due to the high overhead in browsers such as Chrome and NodeJS. The performance issues can be resolved, as demonstrated by Mozilla

Another advantage of Wasm is its portability. Because it is designed to run in any modern web browser, it allows developers to write code that can be run on any device with a web browser, regardless of the operating system or architecture. This makes it possible to create applications that can be used on a wide range of devices, from desktop computers to smartphones, without the need to write separate versions for each platform. This improved portability can make it easier for developers to reach a wider audience, as their applications can be used by a larger number of users on different types of devices without the downsides of modern approaches such as Progressive Web Apps or frameworks like React Native

Wasm also has the potential to improve the security of web applications. Because it is a low-level language, it is less susceptible to certain types of security vulnerabilities that are common in higher-level languages such as JavaScript. In addition, Wasm is designed to be run in a sandboxed environment, which prevents it from accessing sensitive parts of the system and reduces the potential impact of any vulnerabilities that may be discovered.

In addition to these technical advantages, Wasm offers ultralight isolation, which makes it ideal for serverless functions. It's the reason Cloudfare Workers support 0ms cold starts worldwide

Overall, Wasm is an important technology for the future of the web. Its performance, portability, and security make it well-suited for a wide range of applications, and its ability to support multiple languages has the potential to expand the web development community. As more and more developers begin to adopt Wasm, we can expect to see a new wave of innovative and high-performance applications on the web.