javascript - How can I monitor the rendering time in a browser?

Question

I work on an internal corporate system that has a web front-end using Tomcat.

1. How can I monitor the rendering time of specific pages in a browser (IE6)?
2. I would like to be able to record the results in a log file (separate log file or the Tomcat access log).

EDIT: Ideally, I need to monitor the rendering on the clients accessing the pages.

Answer 1

The Navigation Timing API is available in modern browsers (IE9+) except Safari:

function onLoad() { 
  var now = new Date().getTime();
  var page_load_time = now - performance.timing.navigationStart;
  console.log("User-perceived page loading time: " + page_load_time);
}