Is this JavaScript playground free to use?

Yes, the DevsCurry JavaScript playground is completely free, requires no signup, and runs entirely in your browser.

Does the JavaScript code run on a server?

No, your JavaScript code executes locally in your browser inside a sandboxed Web Worker, ensuring high execution speed and total privacy.

How does the playground handle infinite loops?

The playground runs code in a dedicated Web Worker with a 10-second watchdog timer. If an infinite loop is detected, the worker is automatically terminated to keep your browser responsive.

Can I format my JavaScript code automatically?

Yes, the playground includes an integrated Prettier formatter. You can format your code with one click or by pressing Ctrl+S / Cmd+S.

Does this playground support modern ES6+ features and async/await?

Yes, the playground runs on modern JavaScript engines and supports ES2020+ syntax, classes, Promises, async/await, and arrow functions.

JavaScript Playground - Run JS Code Online

Name: JavaScript Playground - Run JS Code Online | DevsCurry
Brand: DevsCurry

Welcome to the DevsCurry JavaScript Playground, a free online coding sandbox designed for developers, students, and educators. Write, test, run, and format modern JavaScript (ES6 / ES2020+) directly in your browser with zero installation and no login required.

Interactive JavaScript Starter Code

This sandbox launches with interactive starter code that you can edit and run immediately:

function greet(name) {
  console.log(`Hello, ${name}!`);
}

greet('world');

Key Features & Technical Specifications

Client-Side Sandboxing: Code executes entirely in an isolated browser Web Worker, preventing cross-origin data exposure and keeping your code private.
Monaco Editor: Powered by the same editor engine as Visual Studio Code, complete with syntax highlighting, line numbers, and autocomplete.
Vim & Emacs Modes: Toggle standard keybindings, Vim emulation (with status bar), or Emacs keybindings directly from the toolbar.
Integrated Prettier Formatter: Keep code clean and properly styled with built-in Prettier standalone formatting (Ctrl+S / Cmd+S).
Interactive Output Console: Streams output directly from console.log(), console.info(), console.warn(), and console.error().
Watchdog Timeout: Automatically terminates execution after 10 seconds if an infinite loop or hanging promise is encountered.
Multi-File Tabs & State Persistence: Create helper files, rename tabs, and your workspace auto-saves to local storage.

Popular JavaScript Examples & Tutorials

Looking for practical JavaScript code snippets? Check out our curated, runnable examples:

Array map() and filter() in JavaScript – Transform and filter collections with functional programming patterns.
Async / Await with Promises in JavaScript – Master asynchronous control flow and delays.
ES6 Classes and Object-Oriented JavaScript – Construct classes, manage state, and invoke methods.

Frequently Asked Questions (FAQ)

Is this JavaScript playground free to use?: Yes, the DevsCurry JavaScript playground is completely free, requires no signup, and runs entirely in your browser.
Does the JavaScript code run on a server?: No, your JavaScript code executes locally in your browser inside a sandboxed Web Worker, ensuring high execution speed and total privacy.
How does the playground handle infinite loops?: The playground runs code in a dedicated Web Worker with a 10-second watchdog timer. If an infinite loop is detected, the worker is automatically terminated to keep your browser responsive.
Can I format my JavaScript code automatically?: Yes, the playground includes an integrated Prettier formatter. You can format your code with one click or by pressing Ctrl+S / Cmd+S.
Does this playground support modern ES6+ features and async/await?: Yes, the playground runs on modern JavaScript engines and supports ES2020+ syntax, classes, Promises, async/await, and arrow functions.