How does online JavaScript Compiler work?

How does online JavaScript Compiler work?
How does online JavaScript Compiler work?

JavaScript is a popular lightweight scripting language. It has gained quite a popularity in recent times. It has been around for almost 25 years now.


It is a versatile language that is being used for almost all different kinds of development. There is JavaScript for frontend development with library and frameworks such as Vuejs and Reactjs, backend development with node.js and deno.js.

Tfjs and ml5 for machine learning in JavaScript. Desktop application development with electronjs. Game development can also be done in it with pixi.js, babylon.js and phaser. With this, you can easily make out how popularly and vastly JavaScript is being used.

You must be getting started with JavaScript and want to get your hand dirty by playing around with the code. It is always troublesome and difficult to make your setups initially for any kind of development. It might even stop you at times when you wish to experiment with some new application. But you need not worry.

There are several solutions available online to resolve this issue. We now have many compiler websites which don’t require you to make your setup on your system but rather compile and run the code in the browser itself. Isn’t it amazing? No need to worry about the setup issues first when you want to begin. You can directly start to code.

These are some of the best platforms available for JavaScript compilers:

1. – Online JavaScript Editor

A really simple and intuitive website created by Rodrigo Siqueira. It is free to register and join the site. You can save your work online. You can also load code from your local machine. You can share your code with the address generated. Overall the performance of the website is pretty smooth and fast. No complex User interface, rather a simple and easy to go with the editor. 

2.  PLAYCODE – Online JavaScript Editor

This is a sophisticated and really amazing code ground. It gives you vscode like interface with themes you can change. It provides you with a greater set of options such as creating projects, using libraries such as jquery and tailwind, add assets. Along with that, it supports HTML and CSS. You also get debug console. 

The live preview has a hot reload feature so that you don’t have to manually reload every time you make a change. The screen is adjustable with the editors, console and view. Play code also supports its preprocessors such as typescript, jsx, tsx and CoffeeScript. There is a facility for sharing the code and hosting. You can add dependencies also such as react, font-awesome and, other CSS and JavaScript libraries.

3. is one of the leading and most powerful online IDE, compiler, interpreter and editor. It can not only compile your JavaScript code but code n more than 50 languages. You have the Node.js online editor for your JavaScript code. You can work on multiple projects simultaneously, connect your GitHub account to access repos in replit and explore other replit projects.


I found this another interesting JavaScript compiler. The reason for putting it here is you can really get a one-stop simple editor for all your code needs. It supports more than 25 languages including SQL, Haskell and C++. The best part from the developer point of view is they have API for you to play around with and use the editor in a project. There are some more options such as themes, code wall to share code and users for the community. You should definitely try it once and see for yourself. It utilises the rhino engine.

Can I make my own compiler?

You can always be curious and think of making your own stuff as a developer. Yes, you can surely make your own compiler or applications that have a compiler. For application purposes, you don’t need to create a JavaScript compiler form scratch but rather utilise API from organisations that already have it built. You can check out You can also learn to make a compiler in it.

Refer to the below articles:

Frequently Asked Questions

Is JavaScript compiled or interpreted programming?

A compiled language such as Java and C++ needs to be compiled completely and converted into executable code before it runs. An interpreted language is read line by line and executed simultaneously. Hence, JavaScript is an interpreted and platform-independent language.

Does JavaScript have a compiler?

No, JavaScript does not have a compiler. JavaScript is interpreted, So there are interpreters. JavaScript interpreters also known as JavaScript engines. Some of the popular ones are the Chrome V8 engine, SpideMonkey. It is often mentioned like the engines compile the JavaScript code to machine code. But that actually is just in time compilation.

How does an online JavaScript compiler work?

The online compilers are webpages where you write your code and these codes are sent to the server which has the compiler built. The result is obtained as a response and rendered on the client-side again.

How does the JIT compiler work in JS?

JIT is just in time compilation. JavaScript is originally interpreted language. The recent JavaScript interpreters/engines such as V8 perform JIT. Rather than using interpreter, they compile JavaScript code into machine code for speed and efficiency.


These compilers are really amazing tool for the newbies in the industry but it is not the permanent solution. It is always better to have your setup where you can save your work locally and run whenever you want without the fear of losing your work. I hope you enjoy your first-hand experience with JavaScript compilers available online.

Happy Learning!