Welcome to HCODX Online Compiler
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Compile and run Node.js code online instantly with HCODX. Our free cloud-based Node.js compiler supports real-time execution, standard input, syntax highlighting, and code download. No installation or configuration required. Start coding in Node.js now.
Run Node.js instantly without installing any IDEs or configuring environments. Our cloud-based Node.js handles libraries, runtimes, and dependencies automatically so you can focus on writing code.
Whether you are studying algorithms in Node.js, practicing data structures in Node.js, or exploring functional programming, our tool provides real-time stdout/stderr feedback with interactive standard input support.
HCODX is a free online compiler and code runner: write code in your browser, execute it on a cloud sandbox, and interact with your program through a live terminal. Students use it for coursework and interview practice; developers use it to test snippets in 85+ languages without setting up a local environment.
Node.js took JavaScript out of the browser in 2009 and turned it into a serious backend platform — LinkedIn, Walmart, Netflix, and Uber all run production services on it, and npm grew into the largest package registry in the world around it. Built on Chrome's V8 engine with an event-driven, non-blocking I/O model, Node excels at APIs, command-line tools, and build tooling. HCODX runs your script on a current LTS release of Node inside a live terminal session: stdout streams in real time and process.stdin is wired to your keyboard, so readline-based prompts behave exactly as they would in a local shell — no nvm, no install.
const readline = require("node:readline/promises");
async function main() {
const rl = readline.createInterface({ input: process.stdin, output: process.stdout });
const name = await rl.question("What's your name? ");
const count = Number(await rl.question("How many greetings? "));
for (let i = 1; i <= count; i++) {
console.log(`${i}. Hello, ${name}!`);
}
rl.close();
}
main();Sketch backend logic before wiring it into Express or Fastify, test JSON transformations and string parsing for an API layer, or answer the classic Node interview questions — event loop ordering, promises versus callbacks, stream behavior — with runnable proof. HackerRank and CoderPad both deliver input over stdin in their Node environments, so practicing here with readline is a one-to-one rehearsal. It's also handy for trying a built-in module like crypto or url without creating a whole project folder. HCODX is a free online Node.js editor, runner and interpreter — an IDE-grade compiler and playground to write and run code online, execute code with live output and live preview, no downloads or web server required.
It does. Your script gets a real terminal, so readline questions, rl.on('line') handlers, and raw process.stdin reads all wait for live keyboard input while the program runs. That makes stdin-driven challenge formats and interactive CLI prototypes work without any workarounds.
A modern long-term-support (LTS) release, so contemporary features — async/await, optional chaining, node: prefixed imports, structuredClone, fetch — are available. If your code depends on behavior from a specific older version, test locally with that exact release before relying on it.
Third-party npm packages can't be installed in the sandbox, and long-running servers aren't the right fit for a timed run. All core modules work, though: fs, http, path, crypto, events, streams. For learning Node fundamentals and interview prep, the built-ins cover nearly everything.
Your current code will be replaced with the default sample. This cannot be undone — download your code first if you want to keep it.
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