Web technologies have been continuously evolving. We’ve transitioned from the simplicity of HTML and CSS to the complex frameworks like Django and React. While building JavaScript applications is still popular these days, a new player called WebAssembly has emerged that could potentially redefine web development. 

In this article, we’re going to unmask everything about WebAssembly to understand why this revolutionising language holds the key to the future of web performance and how it transforms the way we run code in browsers.
Today this technology is adopted beyond the browser, WebAssembly has become available on the Edge Platforms and shortly, It will also be used also on the server side.  

What is WebAssembly?

Often known as WASM, WebAssembly is an open standard that defines a binary format and corresponding assembly-like text format for executable code in web pages. As we all know, running non-web languages like C++ and Go can invite unneeded security concerns in the form of malicious attacks. 

However, WebAssembly sorts this issue by allowing you to run high-level programming languages on your browser without leaving any gaps for such occurrences. It partially achieves this by converting the generic language format into a similar script as machine code.

It is conceived by the World Wide Web Consortium (W3C), and aims to enhance and improve web performance by enabling high-level languages to function naturally within a web context. 

Yes, it’s not really a programming language in a traditional sense; instead, it can be classified as a compilation target for other languages. You could also think of it as a form of machine code that runs in a browser - much like JavaScript. 

However, unlike JavaScript, WebAssembly is considered as a separate entity, allowing developers to use both JavaScript and WebAssembly in tandem to achieve performance that was previously unattainable!


How Does WebAssembly Work?

Before jumping right into the nitty-gritty, let’s first understand what “compilation target” means. You see, high-level languages such as Rust, C++, and Go, are compilable into WASM bytecode, which can then be executed at near-native speeds by the browser. 

Due to this process, WebAssembly runs code faster, and more efficiently than even JavaScript - dethroning it in not only speed, but effectiveness as well!

Security and Integrity

WebAssembly operates within a secure sandbox environment, isolated from the rest of the client's system. This means no one can access sensitive client resources, such as files, network connections, or other parts of the host system. 

Plus, it is a low-level bytecode representation. Remember, the client’s processor isn’t the one executing it, rather, a WASM engine within the browser is responsible for the execution. So, we’re essentially getting a linear memory model, where WASM has its own memory space, and it can only interact with the same origin from which it is loaded. 

So, how does it interact with JavaScript then? The answer lies in defined interfaces. These are controlled and limited, preventing WASM code from executing arbitrary JS code directly, thereby making WebAssembly more secure than ever!

Use Cases for WebAssembly

Due to its special characteristics, you can expect WebAssembly to be used in every computation-extensive application. 

Here are a few examples:

Example Application
Gaming WASM has made browser-based gaming more powerful and efficient. High-end, graphics-intensive games can now run smoothly in a browser while offering a native-like experience.
Image and Video Editing In this day and age, web applications have taken over a lot of the heavy-lifting your storage used to do. Keeping that tradition alive, Browser-based photo and video editing tools can leverage WASM’s speed and performance to provide a smooth experience!
Music Production and Audio Processing WASM’s performance characteristics make it an excellent choice for online music production and real-time audio processing tools.
Scientific Simulations Handling complex computation and data means visualisation, and scientific simulation is a piece of cake for WASM.


In essence, WebAssembly and its underlying language form the backbone of a revolution in how we use our browsers. With one of the only major limitations lifted, it will be exciting to see what the next chapter brings to the table. 

For all we know, WASM in browser might just be preparing us for an era where the line between ‘web’ and ‘native’ becomes increasingly blurred!

Published on:
December 28, 2023
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