WebAssembly vs JavaScript: Which One to Choose?


June 2, 2023


June 5th, 2023

Category JavaScript, JS

Be it the creation of complex web apps or responsive mobile apps, developers look for robust programming languages that can be their support system. JavaScript is one such language that has been ruling the charts over the years. Over the last few years, there is yet another natively supported programming language, that is compared with JavaScript – WebAssembly, also known as WASM.

WebAssembly vs JavaScript is an interesting evaluation that is often done by developers, with respect to multiple features. WASM and JavaScript have been closely linked, yet both have their individual purposes to serve. Initially, the main aim of WebAssembly was to help JavaScript execute more effectively in the web browser.

But now it has moved beyond mere assistance to JavaScript and has an individual entity now, as an effective tool. JavaScript acts as the glue that connects WebAssembly modules into web browsers.

WASM and JavaScript integrate seamlessly for a range of applications like browser-driven ML solutions, AR and VR reality apps, browser-based games, etc.

This article compares the two languages – WASM vs JavaScript and answers a few queries – will WebAssembly take over JavaScript? Is WASM faster than JavaScript? It also talks about WebAssembly vs js performance, and how WebAssembly may not dethrone JavaScript but, has a fanbase of its own.

What is WebAssembly?

WebAssembly (abbreviated WASM ) is a binary instruction format for a stack-based virtual machine. Wasm is designed as a portable compilation target for programming languages, enabling deployment on the web for client and server applications.

WebAssembly is a popular assembly cum programming language that is based on universal low-level bytecode, closer to machine code. It completes compilation and resource loading prior to execution in the browser.

It is standardized with all major browsers (Google Chrome, Mozilla Firefox, Microsoft Internet Explorer, and Apple Safari) and there are many programs that are executing seamlessly like Google Earth, Adobe Acrobat’s in-browser app. Developers can execute performance-based business logic code at a fast, effective speed.

WASM is a novel type of code that is small, low-level, has a binary format for a stack-based VM, and is meant for modernized browsers. It enables web deployment for server and client-side applications. The Wasm modules provide a compilation target for C, C++, Rust, TypeScript, etc.

Its text format empowers faster and easy collaboration between languages. WebAssembly has been a developer’s favorite for the creation of high-performance and seamless web apps that can be at par with native apps.

WASM is compiled till the binary code and hence it has a faster performance with a high runtime speed. It does have compilers that can compile the preferred language and hence coding at a low level does not come out as a tough task. It makes use of binary format with two files – an executable .wasm file and a text .wat file.

The major aim of WASM is to execute effective and modernized browser-based apps at a high-performance speed. There are certain basic concepts on which WebAssembly is built: Values – value types representing listed types like integers, Module – section of executable machine code compiled by browser, Table – an array of values of items including pointers and Functions – organized code blocks that exchange values as parameters.

What is JavaScript?

JavaScript powers thousands of web and mobile apps and it is one of the most popular programming languages in the software development world. JavaScript’s usage has evolved beyond the client side, and it is being used in server-side, game development, and cross-platform development. Some of the popular JavaScript frameworks are React, Angular, Vue, etc.

JavaScript is a platform-agnostic language that runs on any device and browser with ease. It is leveraged for mobile and desktop applications, WebUI, and server-side rendering and deployment.

It forms the foundation stone of multiple applications and compiles the code while it runs in the browser. This could lead to slow performance. Developers can develop diverse applications such as web apps, mobile apps, web portals, dynamic websites, and custom JavaScript applications.

JavaScript was meant to be an easy and effective scripting language that can offer interactive web app development. It is developer friendly and simple, leading to its ever-rising popularity. JavaScript offers a myriad of benefits and support for modern devices, apps, and platforms. JavaScript is a widely used language in almost all types of web apps and one of the core technologies in the World Wide Web along with CSS and HTML.

JavaScript offers development services in a wide range of industries like supply chain and logistics, education, travel, hospitality, etc. All browsers have JavaScript engines for better execution. As an event-driven language, it helps develop interactive and responsive websites, with efficacy. It offers a feature of just-in-time compilation that can create lags for longer tasks but works well with smaller ones. Developers have also created libraries and frameworks that can unlock the potential of JavaScript optimally.

Here, a browser executes code with the JS engine, which has a memory stack that allocates memory and a call stack that tracks the program. Many developers learn about JavaScript through different libraries and frameworks like React js, Vue js, Angular js, etc. It makes use of Google’s V8 engine that is used by Node.js’s server-side framework.

WebAssembly vs JavaScript: Pros and Cons

Pros of WebAssembly:

  • Cross-platform compatibility
  • Portability, top-notch security
  • Statically typed
  • Faster performance and loading times
  • Almost native code with no installations
  • Compilation of coding language into machine code
  • Uses the same web APIs availed by JavaScript
  • Easy debugging through binary files
  • Faster server-side ahead-of-time compilation

Cons of WebAssembly:

  • Early stages of development
  • Low-level language hence complicated
  • Lack of garbage collection

Pros of JavaScript:

  • Compatible with all browsers and devices
  • Variety of existing libraries and frameworks
  • Execution on the client side saves bandwidth
  • Versatile, flexible, easy, and simple to learn
  • Interpreted language with optimal performance
  • Increased developer productivity
  • Enriched user interfaces
  • A wide ecosystem of platforms, developers, frameworks
  • Can be used for frontend and backend code development

Cons of JavaScript:

  • Inefficient debugging support
  • Cross-platform complexities
  • DOM interpretation

WASM vs JavaScript: Organizations Using Them

Companies Using WebAssembly:

CloudFlare, Fastly, Retool, American Express, LanzaTech, Google Earth, Hash.ai, Styra, Cubbit, Foretag, Fivnex, Sheetless, etc.

Companies Using JavaScript:

Microsoft, Google, eBay, Walmart, WebClues Infotech, LinkedIn, Groupon, PayPal, Uber, Netflix, Airbnb, Reddit, Instagram, etc.


WebAssembly vs JavaScript: A Quick Comparison

Parameters WebAssembly JavaScript
Overview  Wasm is faster, delivered through a small-sized binary format, and strongly typed.

It executes complex code effectively and overcomes its load time delay.

It supports complex and sophisticated operations.

JavaScript is dynamically typed, highly flexible, and delivered in human-readable code.

It executes effectively when code is simple because it runs almost instantly rather than compiling first.

It supports simple user interactions and app structures.

WASM vs JavaScript Performance It has strong type code; hence it is optimized before going to the browser and hence faster.

In WebAssembly Vs js performance, it uses small binary files and ahead-of-time processing and works faster.

It is an interpreted language; hence it will take some time to execute and understand what is to be done.

In Wasm Vs JavaScript Performance, it has a long history of usage with multiple devices and browsers supporting it still.

Security Wasm implements in a sandbox offering better security JS works well for smaller tasks with a completely secure environment
Loading Time Loading time is fast for heavy computations Loading time is fast for small and simplistic tasks
Portability Highly portable, can be used in and out of browser platforms Can be used for multiple platforms and use cases
Garbage Collection It relies on JavaScript for garbage collection It has a detailed garbage collection process for memory management
Memory Utilization Complicated memory usage, manual management of memory allocations JavaScript garbage collection automatically takes care of effective memory utilization
API Access It does not have a direct API access It has an extensive platform API access
Debugging Facilities Since it is a compiled language, debugging takes place prior to compilation and hence it is error-free Since it is an interpreted language, debugging takes place with runtime, and hence errors may continue to occur
Multithreading No support for multithreading can use other low-level languages Single-threaded support multiple executions

Also Read: TypeScript vs JavaScript: Is TypeScript A New JavaScript?

WASM vs JavaScript – When to Use What?

As you come across a very common question – ‘Is WebAssembly faster than JavaScript?’, here are certain situations in which you can choose either, based on organizational needs. The decision could vary based on many other parameters but the below can be a guideline to all:

When Should You Use WebAssembly?

As and when we compare WebAssembly vs JS performance, there are certain areas and use cases where WebAssembly can fit better.

  • Computing intensive apps
  • Apps with encryption of sensitive data
  • Hybrid platform apps
  • Video rendering/streaming apps
  • Music streaming apps
  • CPU intensive games
  • Image caching/processing apps
  • High-performance scientific simulation apps

When Should You Use JavaScript?

JavaScript has been a developer’s delight for years now. When there is a comparison of WebAssembly vs JavaScript performance, there are certain use cases that are best fit to be developed using JavaScript and its related frameworks:

  • Embedded systems
  • Desktop applications
  • Mobile applications/games
  • UI for web apps
  • Server-side apps with Node.js
  • Creating web and mobile apps
  • Building web servers
  • Adding interactive behavior to apps
On a Concluding Note

Whenever we start comparing WebAssembly vs JavaScript, it feels as if WebAssembly may overtake JavaScript but that is not possible. It will have its own existence and own fan base, but JavaScript will continue to reign.

Selecting the best option depends upon the user case. There are many factors on which the selection of Wasm vs JS depends on – availability of productivity tools, project deadlines, budget estimates, skilled resources, knowledge of programming languages, etc.

You need a team of professionals who can help you decide your option and draw a detailed roadmap for your project, leading it to success. You just need to select the right IT partner to garner scalability, reliability, and agility in all your business operations.

Our JavaScript developers are well-versed in various JavaScript frameworks and libraries to deliver interactive front-end and robust back end of applications. With SPEC INDIA’s JavaScript development services, you can utilize JavaScript’s versatility to build truly engaging, interactive, and seamless web applications.

Tap into the power of JavaScript to build dynamic and diverse web applications by hiring JavaScript developers from SPEC INDIA. Gain access to top talents with years of experience in different domains and competence to work with modern JavaScript frameworks.

Contact us with all our project details and we will assist you finalize your IT roadmap and select your preferred technology stack.


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