How to use JS Online Editor
- Enter or paste your text into the input field to begin.
- Select Run and the result updates immediately, with no upload.
- Finish by choosing Copy to take the output with you.
About this tool
There is no server behind JS Online Editor. JS Online Editor runs the JavaScript you write inside a sandboxed iframe in your browser and shows whatever you log to the console.
It runs browser JavaScript, not a server runtime, so Node-specific APIs are not available. Your code runs in a sandboxed iframe isolated from this page, with no access to your cookies or storage, and nothing you write is uploaded.
Frequently asked questions
How do I use JS Online Editor?
Use JS Online Editor to process your input without installing anything; everything happens client-side.
Does JS Online Editor cost anything?
No — JS Online Editor is completely free, with no sign-up and no hidden limits.
Where is my data processed by JS Online Editor?
Entirely in your browser — JS Online Editor keeps your data on your own machine and sends nothing anywhere.
Is the code in JS Online Editor really sandboxed?
Yes — JS Online Editor runs your code in an iframe with the sandbox attribute and a separate origin, so it cannot read this page, your cookies or your storage.
Does JS Online Editor work on mobile?
Yes — JS Online Editor is just a web page and runs on any modern browser, including phones and tablets.