title: Can I render warning message if user's browser is not supported?
body: <p>I am working on a <strong>react</strong> application and customers want it to show a special message if user's old browser does not support <em>(e.g. IE 9)</em>.</p>
  
  <p>So long I tried to detect some "popular" old browsers, using <code>react-device-detect</code> package. </p>
  
  <p><strong>src/index.js</strong></p>
  
  <pre><code>import { browserName, browserVersion } from "react-device-detect";
  
  const render = Component =&gt; {
    if (browserName === "IE" &amp;&amp; browserVersion &lt; 10) {
      ReactDOM.render(&lt;UnsupportedBrowser /&gt;, document.getElementById("root"));
    } else {
      ReactDOM.render(
        &lt;AppContainer&gt;
          &lt;Component store={store} history={history} /&gt;
        &lt;/AppContainer&gt;,
        document.getElementById("root")
      );
    }
  };
  </code></pre>
  
  <p>And putting conditional comments:</p>
  
  <p><strong>public/index.html</strong></p>
  
  <pre><code>&lt;!--[if lte IE 9]&gt;
    Please upgrade your browser
  &lt;![endif]--&gt;
  </code></pre>
  
  <p>But I have a suspicion, that there are better ways of doing it, which I could not find searching the web.</p>