title: What is the best way to measure Client Side page load times?
body: <p>I'm looking to monitor the end user experience of our website and link that with timing information already logged on the server side. My assumption is that this will require javascript to to capture time stamps at the start of request (window.onbeforeunload) and at the end of loading (window.onload). Basically this - "<a href="http://www.javaworld.com/javaworld/jw-11-2008/jw-11-measuring-client-response.html" rel="noreferrer">Measuring Web application response time: Meet the client</a>"</p>
  
  <ol>
  <li>Is there a better approach?</li>
  <li>What kind of performance penalty should I be expecting (order of magnitude)?</li>
  <li>How good are the results?</li>
  </ol>