📝 Code Editor (Ctrl+Enter to run)
🖥️ Console Output
Click "Run" to see output...
Browser-based JS code editor & sandbox with instant execution and console output
Zero Dependencies · Works Offline · No Data UploadThe JavaScript Playground is a free browser-based code editor and execution tool that lets you write and run JavaScript code without installing any development environment. It supports all ES6+ syntax features, provides complete console output (log/warn/error/table/time), includes multiple code example templates, and supports code snippet saving and management. All code runs in your browser's sandbox — data is never uploaded to any server.
1. Write or paste JavaScript code in the editor, or select a template from the dropdown menu
2. Click "▶ Run" or press Ctrl+Enter to execute the code
3. View results in the console output area — different output types are color-coded (normal/warning/error/info)
4. Click "Save" to save code as a snippet, then load it from the snippet list on the right
5. Use "Copy Code" to copy to clipboard, or "Download" to save as a .js file
Developers can quickly verify an API usage, algorithm logic, or syntax feature before writing project code — no need to open an IDE or create temporary files. Especially useful for testing solutions during coding interviews.
Students and teachers can run code examples directly in the browser, observe output, and understand concepts like closures, prototypal inheritance, and async programming. The 8 built-in templates cover core knowledge points.
Quickly test regex match results, date formatting, string methods, and other browser native API behaviors — more convenient than typing in the console, with the ability to save and reuse test code.
Practice common front-end interview coding problems (debounce, throttle, deep clone, Promise implementation) in the sandbox, and save your own collection of code snippets.
The JavaScript Playground uses the browser's native Function constructor and eval mechanism for sandboxed execution. Unlike Node.js, browser-side JS can access DOM APIs and Web APIs (fetch, localStorage, Canvas, etc.) but cannot use Node.js-specific modules (fs, path, http). ES6+ syntax is widely supported in modern browsers, including optional chaining (?.), nullish coalescing (??), and logical assignment (||=/&&=/??=) from ES2020+. For more complex project development, professional IDEs like VS Code with Node.js runtime are recommended.
A free browser-based JS code editor and execution tool. Write JavaScript code and run it instantly, viewing console output. All code runs locally in your browser.
All ES6+ syntax supported by the browser: arrow functions, async/await, destructuring, template literals, Promises, and more. Full console output methods and DOM operations.
No! All code runs locally in your browser. Nothing is uploaded. Snippets are saved in localStorage and never leave your device.
The tool auto-saves your recent edits. You can also manually save snippets with custom names (up to 20). Load them from the snippet list anytime.
A 5-second timeout prevents infinite loops from freezing the browser. Code exceeding this limit is terminated automatically. Add reasonable exit conditions to loops.
Browser native APIs are available. Dynamic CDN loading isn't supported, but import() for ES Modules works in supported browsers. Best for pure JS logic verification.
console.log (normal), console.warn (yellow), console.error (red), console.info (blue), console.table (table), console.time/timeEnd (timing). All with timestamps.