Can I run JavaScript code online here?

Yes. This page runs JavaScript in your browser using the browser's own JavaScript engine. Nothing needs to be installed.

Is this JavaScript playground free?

Yes. The editor, runtime and examples are free to use, and no account or payment method is required.

Is my JavaScript code uploaded?

No. Code runs inside this browser tab. The sandbox blocks network access, and SkillAIVibe does not receive or store the code you type.

Free browser compiler

JavaScript online compiler

Your code runs on the browser's own JavaScript engine, inside the same network-isolated sandbox everything else here uses. There is nothing to download, so the first run happens immediately. How the sandbox works, and its honest limits, is on the code execution and security page.

the browser's own JavaScript engine

Press Esc then Tab to move keyboard focus out of the code editor.

stdin (one value per line, read by readline())

Output will appear here after you run your code.

Not sure what to type?

A blank editor is the hard place to start. The JavaScript exercises hand you a program that already runs and ask you to change one thing.

Other playgrounds

JavaScript playground questions

Can I run JavaScript code online here?: Yes. This page runs JavaScript in your browser using the browser's own JavaScript engine. Nothing needs to be installed.
Is this JavaScript playground free?: Yes. The editor, runtime and examples are free to use, and no account or payment method is required.
Is my JavaScript code uploaded?: No. Code runs inside this browser tab. The sandbox blocks network access, and SkillAIVibe does not receive or store the code you type.