WebAssembly vs JavaScript | Which is Better?

Whether designing web pages or building complicated mobile apps, developers need stable coding languages that support their work. For more than two decades, JavaScript has been the obvious choice for developers adding interactive features to web apps. Over the last few years, though, a new option has emerged: WebAssembly.

There are plenty of WebAssembly vs JavaScript debates. Which one has better security? Which one can more Web browsers interpret?

In the following, we will compare and contrast these options. Realistically, neither stands out as a universally better choice. You might find, however, that the answer to your WebAssembly vs JavaScript question depends on your priorities.

WebAssembly vs Javascript

It takes years to master JavaScript and WebAssembly. The following WebAssembly vs JavaScript descriptions covers the basics so you can start to understand how they work.

What is JavaScript?

JavaScript (JS) is a high-level language often used alongside HTML and CSS. It has dominated web development for decades with little competition from other coding languages.

It plays such a critical role that all major browsers have JavaScript engines that can execute client-side code.

The event-driven language makes websites more interactive and responsive to users. JavaScript's just-in-time compiling has the potential to create lags during complicated tasks, but it works well for executing small, quick tasks.

Several groups have honed JavaScript’s functionality by creating libraries and frameworks built on the language.

For example, Facebook created the React JavaScript library and released it as an open-source option for building user interface (UI) components in 2017. Similarly, Google created and released the Angular JavaScript framework.

Other JS libraries and frameworks include Svelte, Vue, jQuery, and Underscore.

What is WebAssembly?

WebAssembly (Wasm) is a platform-independent, low-level compiler that makes it possible for developers to add more programming languages to their web applications.

Eventually, WebAssembly’s curators hope it will function within all major browsers.

Currently, Wasm has shipped to four Web browsers (Google Chrome, Mozilla Firefox, Microsoft Internet Explorer, and Apple Safari).

Unlike JavaScript, Wasm isn’t a programming language. It’s an assembly language with the ability, at least theoretically, to compile any language into a format that Web browsers can understand.

WebAssembly uses a binary format that delivers two files;

• ‍an executable .wasm file that Wasm’s virtual machine can run and
• ‍a text .wat file that humans can read in text editors

This approach helps Wasm work at high speeds. JavaScrit relies on just-in-time (JIT) compilation. Wasm can use JIT or ahead-of-time (AOT) compilation.

It's ability to compile language ahead of time means that users can expect faster load times. Precisely how much faster Wasm is than JS is a subject of debate.

It’s important to note that WebAssembly curators say that the code is a complement to JavaScript, not a replacement.

They believe that JavaScript will retain its position as the Web’s leading dynamic language. WebAssembly can, however, make it possible to add more languages to the Web.

WebAssembly vs JavaScript: pros and cons

Let's take a quick look at the pros and cons of WebAssembly vs JavaScript to gain a better understanding of what they offer.

WebAssembly advantages

1. Small files give users faster loading times
2. Nearly native code with no installations, local security concerns, or used disk space
3. Can use the same web APIs accessed by JavaScript
4. Compiles a growing number of coding languages into machine code
5. WebAssembly binary files make debugging easier for humans with access to text
6. Server-side ahead-of-time compiling makes Wasm faster than JavaScript

JavaScript advantages

1. Widely used by developers around the world
2. Understood by all major browsers and nearly all Web browsers
3. Existing libraries and frameworks make it easy for developers to choose the functions they need most when building web apps, mobile apps, and other digital products
4. Saves bandwidth by executing on the client-side instead of the backend

WebAssembly disadvantages

• Lacks garbage collection (GC) for automatic memory management (although there are plans to add GC)
• Relies on JavaScript to interact with the Document Object Model (DOM) instead of interacting with it directly
• Potential security issues could make it easier for criminals to hide malware, phishing attempts, etc

JavaScript disadvantages

• Configuration requires a lot of effort for large projects
• DOM interprets JavaScript slowly compared to HTML and Wasm
• Client-side security can put users at risk

WebAssembly vs JavaScript critical differences

So, what are the critical differences that should influence your decision whether to choose WebAssembly vs JavaScript?

Wasm compilers could add more languages to the Web

Wasm's directors want to add more languages to the Web by adding compilers that can turn languages like C# into Wasm. It's an ambitious goal that could help redefine how the Web serves users and organizations.

Nearly 65% of software developers around the world use JavaScript, making it the most popular language. Still, a sizable percentage of programmers use C# (27.86%), C (21%), and C++ code (24.31%).

With Emscripten, which compiles to Wasm, developers can compile existing C/C++ code and web browsers. Emscripten can also compile C and C++ projects to wasm runtimes and Node.js.

The Clang front-end compiler offers additional support for Rust, TypeScript, Ruby, Java, Julia, Ring, Zig, and Python, the third-most-popular programming language (48.24%).

Yes, asm.js can also compile C coding for use within web browsers. Asm.js, however, is an optimizable, low-level subset of JS. It works well within most contexts, but it isn’t a long-term solution.

At best, asm.js is a hack that can force some C programming to function within a browser. It also suffers from a lack of standardization. Some environments can interpret asm.js much better than others.

Since WebAssembly code has a cross-platform standard, developers will typically get better, more consistent results from it.

The Verdict: If you want to stay at the forefront of development, start using WebAssembly.

JS works across devices and browsers

Relying on WebAssembly as a compiler for diverse languages will almost certainly influence digital technology’s future.

That doesn’t always mean much when you need to build products for immediate use. If you expect to reach anyone outside of the four most popular browsers, it makes sense to use JavaScript.

Additionally, WebAssembly’s ability to compile practically any language means that your JS knowledge doesn’t go to waste. Eventually, you will just use it in a slightly different way.

Some of the core differences between Wasm and JS include but are not limited;

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In conclusion

Choosing which option is best for your project it depends on each use case due to its nature of specifics.

Because of the importance of whether one should decide using Wasm or JS, it is preferred to have a professional team to do such prior assessments always having in mind the goals of that project.

If you face difficulties doing this with your current team, it is advised to collaborate with outsource experts for a safer project development.

Choosing the right option gives you future reliability, scalability, efficiency and agility, all crucial business concept for scale.

Reach out and lets us know your project details and help you weigh the pros and cons of each approach.