Thursday, November 19, 2009

Using eValid to Tune Web Pages

We have had a number of users ask us how to improve the performance of their web pages?

Usually that means that they have some page that is slow or sluggish and they want to know the features of the page that are causing the problem. And, that requires being able to look at pages as they load and see what is going on.

There is a way to do this very simply with eValid, described in our Using Paused Playback to Study Page Timing data.

In a nutshell what this amounts to is to (a) set the timing level for eValid's EventLog to "Detailed," (b) run a script with a Breakpoint command to have eValid "Pause" with the browser active, and then (c) study the details about all of the page components to find where a performance problem lies.

This process builds intuition very quickly, because the detailed timing data reports every page component's size, download speed, and order of completion. Try this on a big website like and you'll be able to see the nearly 200 page elements that make up what you see in the finally-composed and rendered browser face.

Try the same on a page that is done with AJAX and you can see the page components that are updated after the original page load is complete.

Users with this kind of detail don't have much trouble finding the "big offenders" in their pages.

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