Initializing WebContainer...
Create or open a file to start
Run a web server to see the preview
A real Node.js runtime that runs entirely in your browser — no install, no signup.
Open a terminal, npm install any package, build an Express.js server and
see it live. If RunKit or Replit is blocked or paywalled, this is a free alternative
to run npm online and learn backend JavaScript.
This is not a fake console: WebContainer boots an actual Node.js environment inside
your browser tab, with a real file system and a real terminal. You get the same
node and npm commands you use locally, but nothing is
installed on your machine and your own code is never uploaded to a server.
npm install in a real terminal.No. Nothing is installed and there is no signup. A real Node.js runtime runs inside your browser via WebContainer, so you can run code the moment the page loads.
Yes. Open the terminal and run npm install like you would locally. Packages are fetched and installed into an in-browser file system, so you can require and use them right away.
Yes. You can build an Express.js server, start it, and the playground shows a live preview of the running server — no deployment needed.
Yes. If RunKit or Replit is blocked, paywalled or asks you to sign up, this is a free alternative that runs Node.js, npm and Express entirely in your browser with no account.
Yes, completely free with no paywall. It is meant for learning and experimenting with server-side JavaScript.