JavaScript Playground
Write and execute JavaScript code in real-time with instant console output
Tip: Press Ctrl+Enter (or ⌘+Enter) to run your code
Code Editor
JavaScriptConsole Output
Privacy First
All code execution happens locally in your browser. Your code never leaves your device and is automatically saved in local storage for your convenience.
What is a JavaScript Playground?
A JavaScript Playground is a REPL (Read-Eval-Print Loop) environment that allows developers to write and execute code snippets instantly. It is an essential tool for rapid prototyping, testing small logic blocks, and learning language features without the overhead of a local development environment.
Our JavaScript Playground uses a custom execution engine that captures all console outputs and provides a full-featured code editor for a seamless experience.
Key Features and Execution Environment
Monaco Editor Support
We use the Monaco Editor (the heart of VS Code) to provide syntax highlighting, IntelliSense, and automatic formatting, making it easier to write error-free code.
Isolated Local Execution
Your code is executed in a sandboxed new Function() scope. This ensures that your snippets run quickly and don't interfere with the global portal state.
Practical Use Cases
- Testing Logic: Quickly verify complex array methods like
.reduce()or regex-based text processing. - Prototyping Classes: Draft object-oriented patterns or function architectures before implementing them in your main project.
- Debugging Snips: Paste code from StackOverflow or documentation to see how it behaves with real data strings.
- Learning Modern JS: Safely experiment with the latest ES2023+ features directly in your browser.
Privacy and Persistence
Unlike other cloud-based REPLs, our tool executes everything client-side. Your code never leaves your computer, and it's automatically saved to your browser's local storage so you can pick up exactly where you left off.
🔒 Privacy Commitment
Like all tools in the Dev Tool Kit, this JavaScript Playground operates 100% client-side. Your data is processed locally in your browser and is never sent to our servers. Privacy is not just a feature; it's our core architecture.