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Compile and run CoffeeScript code online instantly with HCODX. Our free cloud-based CoffeeScript compiler supports real-time execution, standard input, syntax highlighting, and code download. No installation or configuration required. Start coding in CoffeeScript now.
Run CoffeeScript instantly without installing any IDEs or configuring environments. Our cloud-based CoffeeScript handles libraries, runtimes, and dependencies automatically so you can focus on writing code.
Whether you are studying algorithms in CoffeeScript, practicing data structures in CoffeeScript, 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.
CoffeeScript, released by Jeremy Ashkenas in 2009, compiles to JavaScript and did more than perhaps any other language to shape modern JS: arrow functions, destructuring, default parameters, and classes all appeared in CoffeeScript before ES6 adopted them. Its whitespace-based syntax strips away braces and semicolons, leaving code that reads close to pseudocode. CoffeeScript 2 outputs modern JavaScript and remains maintained, and the language still lives in long-running Rails codebases, older Atom-era packages, and GitHub's historical tooling. This page compiles your CoffeeScript and runs it on Node.js in an interactive terminal, so readline prompts wait for real typed input while console output streams back live.
square = (n) -> n * n
console.log "Hello from CoffeeScript!"
console.log "#{n} squared is #{square n}" for n in [1..4]
inventory =
apples: 3
bananas: 5
console.log "#{fruit}: #{count}" for fruit, count of inventory
readline = require 'readline'
rl = readline.createInterface input: process.stdin, output: process.stdout
rl.question 'What is your name? ', (name) ->
console.log "Welcome, #{name}!"
rl.question 'Favorite number? ', (num) ->
console.log "#{num} doubled is #{Number(num) * 2}"
rl.close()CoffeeScript work today is mostly maintenance and translation: developers inheriting Rails apps with .coffee asset pipelines, teams decommissioning Atom editor packages, and engineers converting legacy code to TypeScript who need to confirm what a tricky comprehension or fat arrow actually does. It also remains a compact illustration for JavaScript history lessons, showing students where ES6 features originated. Running suspicious legacy snippets here, with real Node semantics and interactive input, is faster than resurrecting an old build chain just to observe one function's behavior. HCODX is a free online CoffeeScript 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.
The compiled output runs on Node.js, so use Node's readline module exactly as in JavaScript: create an interface over process.stdin and call rl.question with a callback. The live terminal keeps the process open and delivers your typed line to the callback, letting you nest questions for multi-step prompts as the example shows.
Your source is compiled by the CoffeeScript 2 compiler, which emits modern JavaScript including native classes and arrow functions, and the result executes on a current Node.js runtime. That means Promises, async/await via CoffeeScript's await keyword, and contemporary built-ins behave the same as they would in a present-day Node project.
For new projects the ecosystem has consolidated on TypeScript and modern JavaScript, which absorbed CoffeeScript's best ideas. Reading fluency is the practical skill: plenty of production Rails and legacy Node code still ships .coffee files, and being able to run, verify, and translate that code accurately is a genuinely marketable maintenance capability.
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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