Both React and ReactDOM are available over a CDN.

<script crossorigin src="https://unpkg.com/react@16/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>

The versions above are only meant for development, and are not suitable for production. Minified and optimized production versions of React are available at:

<script crossorigin src="https://unpkg.com/react@16/umd/react.production.min.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@16/umd/react-dom.production.min.js"></script>

To load a specific version of react and react-dom, replace 16 with the version number.

If you serve React from a CDN, we recommend to keep the crossorigin attribute set:

<script crossorigin src="..."></script>

We also recommend to verify that the CDN you are using sets the Access-Control-Allow-Origin: * HTTP header:

This enables a better error handling experience in React 16 and later.