Editors

Your first frontend pen

A 60-second tour of the frontend pen — HTML, CSS, JavaScript, with preprocessors and the live preview iframe.

Last reviewed Apr 22, 2026

A frontend pen has three editors — HTML, CSS, JavaScript — plus a live preview. Press Ctrl/⌘ + Enter to run, or enable LiveEdit for as-you-type updates.

1. Pick a preprocessor (optional)

Each editor has its own preprocessor menu. CSS supports SCSS, Less, Sass, Stylus, and PostCSS. JS supports Babel, TypeScript, CoffeeScript, LiveScript, and Angular.

2. Add external resources

Open Settings → CSS / JS and paste a URL. Or pick from the popular chips: jQuery, React, Tailwind, Three.js, Day.js.

3. Share the room

Click the LiveEdit button, then copy the invite link from the status bar. Anyone with the link joins instantly — no signup required for guests on public pens.

Tip

Press ? anywhere in the editor for the shortcut overlay.

Was this article helpful?

Your feedback shapes our docs.