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 — this free in-browser Node.js playground executes console.log, async/await, timers, process, Buffer and require shims instantly with no server. Ideal for testing JavaScript logic, learning the event loop and debugging snippets before pasting into a real project. No sign-up, no upload, no install — your index.js auto-saves locally and never leaves your device. Works fully offline after page load on desktop and mobile, covering logic and timers (native fs and npm install need installed Node).
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.
Can I test JavaScript array methods in this Node.js playground?
Yes — map, filter, reduce and find run instantly here, ideal for interview practice. For DOM output use the JavaScript compiler.