Code
Output
Click "Run" to see output...
About JavaScript Runner
Need a quick way to verify JavaScript code snippets? This tool executes JavaScript directly in the browser, captures console.log/warn/error/info output, and shows execution time. No Node.js or IDE needed. Perfect for quick experiments, learning, and debugging. Code runs in a browser sandbox, nothing is uploaded.
How to Use
- Open the JavaScript Runner tool page
- Enter or paste your data into the input area
- View the real-time results and use the copy button to get the output
Use Cases
- Verify algorithms — Paste code snippets and see results and output immediately.
- Learn JavaScript — Practice while learning with real-time execution feedback.
- Debug regex — Quickly test regex match results without switching tools.
- Verify data processing — Test JSON parsing, array operations, and data processing code.
FAQ
Is it safe?
Code runs via new Function in the browser, isolating the global scope. However, do not run untrusted code.
Does it support ES6+?
Yes. The browser natively supports all modern JavaScript syntax including async/await, arrow functions, destructuring, etc.
Can I use DOM APIs?
You can access document and window objects, but modifications may affect this page. Stick to pure logic.
Does it support Node.js APIs?
No. This is a browser environment without require, fs, process, or other Node.js APIs.
Comments
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