How to use Online JS Compiler
- Type or paste your text into Online JS Compiler's input area.
- Hit Run — the processed output appears below at once.
- When it looks right, Copy to save it.
About this tool
Everything Online JS Compiler does happens on your own device. Online JS Compiler executes your snippet in an isolated sandbox and prints the console output, all on your device.
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
What does Online JS Compiler do?
Online JS Compiler runs entirely on your device: add your input, and it processes it locally in real time.
Is Online JS Compiler free to use?
Yes — Online JS Compiler is completely free, with no usage limits.
Where is my data processed by Online JS Compiler?
Entirely in your browser — Online JS Compiler keeps your data on your own machine and sends nothing anywhere.
Is the code in Online JS Compiler really sandboxed?
Yes — Online JS Compiler 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 Online JS Compiler work on mobile?
Yes — Online JS Compiler is just a web page and runs on any modern browser, including phones and tablets.