React online coding platform
Build React UIs in the cloud, no local setup needed.
Start coding free →React in the cloud, ready in under a minute.
React is a JavaScript library for building user interfaces, developed by Meta. It centers on reusable components, a virtual DOM for efficient updates, and JSX syntax that lets you write HTML-like code in JavaScript files. Open a RunCode workspace and your React environment is ready in under a minute, with Node.js, npm, and VS Code already in place.
Open a React workspace →Components, virtual DOM, and state
React organizes a UI into components: self-contained pieces of code that can be reused and composed across an application. The virtual DOM tracks what changed and updates only the affected parts of the page, keeping interactions fast as the app grows. JSX lets you describe UI structure directly in JavaScript files, which most developers find easier to follow than separate template files. React's state mechanism stores and updates data within a component so the interface stays in sync with your data. It is widely used for web apps, single-page applications, and mobile UIs via React Native.
What you get on RunCode for React
Select the React template when you create a workspace. VS Code opens in your browser with Node.js, npm, and a terminal already configured. Run npm run dev and you are writing components straight away, with no local toolchain to install or configure.
- Node.js and npm preinstalled
- VS Code running in your browser
- A full Linux terminal for scripts and tooling
- Git integration with GitHub, GitLab, and Bitbucket
- A workspace ready in under a minute