react-native-web/docs/guides/react-native.md

React Native

This is an experimental feature to support: using community-developed React Native components on the Web; and rendering React Native apps to Web.

Use a module loader that supports package aliases (e.g., webpack), and alias react-native to react-native-web.

// webpack.config.js

module.exports = {
  resolve: {
    alias: {
      'react-native': 'react-native-web'
    }
  }
}

Web-specific implementations can use the *.web.js naming pattern, which webpack will resolve.

Minor platform differences can use the Platform module.

import { AppRegistry, Platform, StyleSheet } from 'react-native'

const styles = StyleSheet.create({
  height: (Platform.OS === 'web') ? 200 : 100
})

AppRegistry.registerComponent('MyApp', () => MyApp)

if (Platform.OS === 'web') {
  AppRegistry.runApplication('MyApp', {
    rootTag: document.getElementById('react-root')
  });
}