Free JavaScript Compiler with Live Execution — runs in your browser

JavaScript Editor
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Console
Click "Run Code" to execute your javascript code...
Try an example:

Pick an example, then press Ctrl/⌘ + Enter or click Run Code. Code runs 100% in your browser — nothing is sent to a server.

✨ Free Online JavaScript Editor with Live Execution

Execute Modern JavaScript Instantly in Your Browser. Run ES6+ JavaScript with full browser APIs. Write async/await, fetch calls, DOM manipulation, and test algorithms instantly. Perfect for learning, testing snippets, and interview preparation.

🚀 Why Choose Our JavaScript Editor?

Native browser JavaScript execution with console output and instant results. 100% free, no registration required, and complete privacy. Your code never touches our servers - everything runs locally in your browser.

Key Features

⚡Instant Execution

Run JavaScript immediately. See console.log output and errors in real-time.

🚀Modern ES6+

Full support for async/await, arrow functions, destructuring, classes, and latest features.

🌐Browser APIs

Access fetch, DOM, localStorage, and all browser JavaScript APIs. Build real web code.

🎯Perfect for Interviews

Solve algorithms, test logic, verify solutions. Ideal for technical interviews and LeetCode prep.

Popular Use Cases

Learning JavaScript

  • • Practice ES6+ syntax
  • • Learn arrow functions
  • • Master async/await
  • • Understand closures
  • • Study objects & arrays
  • • Practice destructuring

Web Development

  • • DOM manipulation
  • • Event handling
  • • Fetch API calls
  • • API integration
  • • Form validation
  • • UI interaction

Interview Preparation

  • • Algorithm practice
  • • Data structure coding
  • • LeetCode problems
  • • Async challenges
  • • Technical assessments
  • • Live coding mock

Algorithm Practice

  • • Array algorithms
  • • Sorting & searching
  • • Recursion problems
  • • Dynamic programming
  • • String manipulation
  • • Math problems

Testing & Debugging

  • • Test code snippets
  • • Debug functions
  • • Verify logic
  • • Check edge cases
  • • Performance testing
  • • Error handling

Teaching & Learning

  • • Code demonstrations
  • • Student exercises
  • • Interactive tutorials
  • • Live coding lessons
  • • Bootcamp teaching
  • • Online courses

JavaScript Features Supported

ES6+ Features

  • ✓ Arrow functions
  • ✓ Template literals
  • ✓ Destructuring
  • ✓ Spread operator
  • ✓ Classes
  • ✓ Async/await
  • ✓ Promises
  • ✓ Modules

Browser APIs

  • ✓ fetch API
  • ✓ DOM manipulation
  • ✓ Event listeners
  • ✓ localStorage/sessionStorage
  • ✓ setTimeout/setInterval
  • ✓ XMLHttpRequest
  • ✓ Web Worker basics
  • ✓ Geolocation API

Data Structures

  • ✓ Arrays & methods
  • ✓ Objects & properties
  • ✓ Maps & Sets
  • ✓ WeakMap & WeakSet
  • ✓ Array destructuring
  • ✓ Object spreading
  • ✓ Regular expressions
  • ✓ JSON parsing

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Frequently Asked Questions

How do I run JavaScript online without installing Node.js?

Simply paste or write your JavaScript in our editor and click "Run Code". The code executes directly in your browser using the native JavaScript engine. No Node.js needed—this is pure browser JavaScript with full ES6+ support. Output appears instantly in the console.

Does this support modern JavaScript ES6+ features?

Yes! Full support for ES6+ including arrow functions, const/let, template literals, destructuring, spread operator, classes, async/await, promises, optional chaining, nullish coalescing, and all modern syntax. Write cutting-edge JavaScript.

Can I use fetch API and DOM manipulation?

Yes! The editor runs browser JavaScript so you have access to all browser APIs: fetch(), XMLHttpRequest, document object, DOM manipulation, localStorage, sessionStorage, console.log, setTimeout, setInterval, and event listeners. Perfect for web development practice.

What is the difference between this and Node.js?

This editor runs browser JavaScript (client-side), so you get browser APIs (fetch, DOM, localStorage) but NOT Node.js-specific APIs (fs, process, require). Perfect for learning JavaScript, testing algorithms, practicing ES6+, and web development. Use Node.js for server-side code.

Can I practice async/await and promises?

Absolutely! Write async functions, use await, create promises, use Promise.all(), Promise.race(), handle errors with try/catch. Perfect for learning asynchronous JavaScript. Output shows immediately in the console.

Is this suitable for JavaScript interviews?

Perfect! Share your screen and solve JavaScript algorithm problems instantly. Commonly used for LeetCode-style problems, data structure challenges, async coding questions, and technical assessments. Console output appears immediately.

Can I test array and object manipulation?

Yes! Practice array methods (map, filter, reduce, forEach), object operations (spread, destructuring, Object.keys/values/entries), and data transformations. Perfect for learning functional JavaScript and data manipulation patterns.

Does it work for learning JavaScript from scratch?

Perfect for beginners! Start with console.log(), learn variables, functions, objects, arrays, conditionals, loops. The instant execution and clear output make it ideal for understanding JavaScript fundamentals. No setup overhead, just start coding.

🎓 Pro Tips for JavaScript Development

  • Tip 1: Use console.log() liberally to debug - output shows in real-time
  • Tip 2: Master array methods like map(), filter(), reduce() for functional style
  • Tip 3: Use const by default, let for variables that change, avoid var
  • Tip 4: Practice async/await instead of promise chains for cleaner code
  • Tip 5: Use template literals for string interpolation: `Hello ${name}`
  • Tip 6: Destructure objects and arrays to write cleaner code
  • Tip 7: Use arrow functions for concise syntax: const add = (a,b) => a + b
  • Tip 8: Learn the event loop to understand asynchronous JavaScript