Free · Browser-Based · No Install Required

HCODX VS Editor For Online HTML & React Code Playground
with Live Preview IDE

A powerful online Web IDE for HTML, Vue, and React — with NPM support, live preview, and a VS Code–like experience. The modern CodePen alternative for serious web development.

Supports
5 HTML5
3 CSS3
JS JavaScript
TS TypeScript
Vue 3
React
Next.js
Three.js
npm npm
Sass

Powerful all-in-one platform to write, run, and preview code instantly. This advanced online IDE supports HTML, CSS, JavaScript, Vue, React, Next.js, and Three.js with real-time live preview, making it the perfect browser-based development environment for frontend and full-stack developers. As a fast, scalable, and cloud-based code editor, HCODX enables users to build responsive websites, test UI components, develop JavaScript applications, and experiment with modern frameworks without installation or setup. Competing with leading platforms like Visual Studio Code, CodeSandbox, and StackBlitz, HCODX delivers high-performance coding, instant compilation, live rendering, and seamless developer experience directly in the browser. Whether you’re looking for a free online code editor, a live HTML preview tool, a JavaScript playground, or a professional web IDE, HCODX Studio is optimized for speed, productivity, SEO visibility, and modern web application development.

Why HCODX Studio
Monaco Editor VS Code engine — IntelliSense, syntax highlighting, Vim/Emacs modes
Live Preview Instant rendering via preview.hcodx.com with CSS hot-patch
Runtime Compiler Vue SFC · React JSX · TSX · TypeScript — no build step
70+ Languages Python, Go, Rust, C++, Java & more via self-hosted Piston API
Lighthouse Audit Performance · Accessibility · Best Practices · SEO analysis
PWA & Offline IndexedDB project storage · No account · Works offline
Choose a Template
Pro starter code — Monaco editor, live preview, and IntelliSense ready instantly.

Featured

More Templates

Write & Run HTML, Vue, and React Code Online

HCODX Studio is a full-featured online web ide that lets you write, run, and preview HTML, Vue, and React applications directly in your browser — no installation, no setup, no account required. Whether you're prototyping a UI, building a full single-page application, or testing a new javascript playground idea, HCODX gives you everything you need: a real html editor online, a fully-featured react playground, and a complete vue playground with Single File Component support, all in one place.

VS Code–Like Editor with Live Preview

Built on the Monaco editor — the same engine that powers VS Code — HCODX Studio delivers a true vscode online editor experience: IntelliSense, syntax highlighting, multi-cursor editing, tabs, a file tree, and command palette. Pair that with our instant live preview code panel and you get a live code editor that updates as you type. Every keystroke renders to a preview iframe in real time, with full support for ES modules, CSS, SCSS, TypeScript, JSX, and TSX.

Full Web Development Playground with NPM Packages

Most browser editors stop at vanilla JavaScript. HCODX is a true npm browser ide: import any package using bare specifiers (import Vue from "vue") and we resolve and load it from a CDN automatically. Bring in React, Vue, Three.js, Chart.js, Tailwind, Lucide icons, GSAP, or any of the millions of packages on npm — and they just work, with no npm install, no bundler config, and no build step.

Fast, Free, and Powerful CodePen Alternative

HCODX Studio is the modern codepen alternative for developers who've outgrown the single-file pen. Multi-file projects, ZIP import & export, IndexedDB persistence, mobile device emulator, Lighthouse audits, and full framework support put it ahead of any traditional pen-style editor. It's free, browser-based, and ready in seconds — the developer playground for serious work.