Preview:
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta name=description content="">
    <meta name=viewport content="width=device-width, initial-scale=1">
    <title>First Component</title>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.13.0-beta.1/react.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.13.0-beta.1/JSXTransformer.js"></script>
</head>
<body>
    <script type="text/jsx">
    /** @jsx React.DOM */
    var APP = React.createClass({
        render: function() {
            return (
                <h1>Hello World</h1>
            );
        }
    });

    React.renderComponent(<APP />, document.body);
    </script>
</body>
</html>
downloadDownload PNG downloadDownload JPEG downloadDownload SVG

Tip: You can change the style, width & colours of the snippet with the inspect tool before clicking Download!

Click to optimize width for Twitter