Explore and experiment with JavaScript and TypeScript, visualise your ideas and get instant feedback as you type.

Exploring JavaScript has never been easier. Live feedback as you type, with per-line results makes it super clear what your code is doing.

With RunJS you have access to Node.js and Browser APIs, including full DOM access. This gives you a level of versatility that's not possible in a standard REPL or Chrome console.

Babel and TypeScript support enables you to write modern, up-to-date syntax.