Run Node without installing
No Node install on your machine. Press Run and see console.log output instantly — perfect for quick tests at school/work.
Free Node.js playground — no install, no sign-up
Run Node.js online — Node.js compiler without installing Node
Run Node.js online without installing Node.js. Write console.log, async/await, timers and require shims and see the console update instantly — free, no sign-up, works fully offline in your browser (MVP).
How to run Node.js online without installing Node.js
Answer in 30 seconds: Open the Node.js compiler above, type Node.js JavaScript into index.js and press Run (or Ctrl+Enter). It runs Node-like JavaScript directly in your browser — no install, no account, offline. After writing, download index.js or copy output.
- 1
Open the online Node.js compiler
No install, no download — Node.js runs as JavaScript in your browser. Works on desktop and mobile.
- 2
Write Node.js code
Use
console.log,process.version,Buffer,setTimeout,async/awaitor paste a snippet. Auto-saves tolocalStorage. - 3
Click Run and see console output
Press Run — output streams to the console including timers and promise results. Copy or download anytime.
Why use this online Node.js playground?
100% offline & private
Code runs only in your browser. No upload, no tracking — safe for private snippets.
Node-like basics
console, process, Buffer, setTimeout, require shim — covers most beginner logic.
Auto-save
Your index.js is saved to localStorage and restored on return.
Async & timers
Test async/await, promises and setTimeout behavior with correct microtask flushing.
Works on mobile
Editor and console stack on phones and tablets — run Node.js logic on the go.
What can you test in this Node.js online REPL?
Direct answer: Test any Node.js JavaScript that uses console, process, Buffer, timers and async/await — all without installing Node. Ideal for learning the event loop and debugging snippets before pasting into a real project.
Console & process
Try console.log(\"Node\", process.version, process.platform) instantly.
Async & await
Test async demo(){ await new Promise(r=>setTimeout(r,300)); console.log(\"done\")} and see timing.
Require shim
Check require('fs') mock behavior and prototype ideas without breaking your local setup.
MVP limits — honest note
This browser MVP does not run real fs, child_process or npm install. For full Node with files and packages, a WebContainers upgrade is planned. Use it today for logic, async, timers demos. For heavy I/O, use installed Node.
Frequently asked questions
How can I run Node.js online without installing Node.js?
Open the FastCompiler Node.js compiler above, type Node.js JavaScript into index.js and press Run. It executes Node-like code directly in your browser — no install, no sign-up, offline.
Is this real Node.js?
It is a browser MVP mimicking core Node: console, process, Buffer, timers, require shim, async. Real fs, child_process and npm install are not yet supported — WebContainers upgrade is planned.
Can I use npm packages?
Not in this MVP. require returns a mock. Use it for logic, async and timers. For packages, use installed Node or wait for WebContainers.
Do I need an account?
No — free, no sign-up. Your index.js auto-saves to localStorage.
Does it work offline?
Yes — runs locally in your browser, no server, fully offline after page load.
Is my code uploaded?
No — execution stays in your browser, never sent to a server.