Html5 rocks

User Timing API: Understanding your Web App – HTML5 Rocks

“High performance web applications are crucial to a great user experience. As web applications become more and more complex, understanding performance impact is vital to creating a compelling experience. Over the past few years, a number of different APIs have appeared in the browser to help analyse performance of the network, load times, etc. but these don’t necessarily give fine-grained detail with sufficient flexibility to find what’s slowing down your application. Enter the User Timing API which provides a mechanism you can use to instrument your web application to identify where your application is spending its time. In this article we’ll cover the API plus examples of how to use it.”

Table of Contents

  • You can’t optimize what you can’t measure
  • High Resolution time and ‘ now() ’
  • The User Timing Interface
  • Getting the timing data out
  • Timing an XHR request (example)
  • Conclusion