jsxrun

Run a single JSX file as a React app — no setup required.

npx jsxrun app.jsx

Install

npm i -g jsxrun

Usage

jsxrun <file.jsx|tsx> [options]

Your file must have a default export of a React component:

import { useState } from "react";

export default function App() {
  const [count, setCount] = useState(0);
  return <button onClick={() => setCount(count + 1)}>Count: {count}</button>;
}

Then run it:

jsxrun app.jsx

Open http://localhost:3000 and you're done.

Options

| Flag | Description | | --- | --- | | -p, --port <number> | Port to serve on (default: 3000) | | -o, --open | Open in browser automatically | | -b, --build | Output a single .html file instead of starting a server | | -h, --help | Show help |

Build a single HTML file

jsxrun app.jsx --build

Outputs app.html — a self-contained file you can open directly in a browser or share. No server needed.

How it works

• esbuild bundles your JSX on-the-fly
• React 19 is loaded from esm.sh via importmap (no local install needed)
• Live-reload via SSE — edit your file, browser refreshes automatically
• --build inlines your bundled JS into a single HTML file
• Supports .jsx and .tsx files

License

MIT