JavaScript Runner
Write and run JavaScript code instantly in your browser. Multi-file support with zip import.
100% In-Browser Processing. Your files never leave your device.
index.js
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Terminal
Press Ctrl+Enter to run
About this tool
JavaScript Runner is a free, browser-based code editor and execution environment for JavaScript. It features a full Monaco editor (the same editor that powers VS Code) with syntax highlighting, code folding, and bracket matching. Your code runs in a sandboxed iframe — completely isolated from the main page for security. You can work with multiple files, import zip archives, and see console output in real time. Everything runs locally in your browser — no code is sent to any server.