How to improve the page load time and rendering time for your ATG application!
How your users and customers perceive the speed of your site is critical. The faster and more responsive your site appears to them the better experience they have and the more likely they are to make a purchase. There are plenty of studies about page response time and abandonment, so I won’t rehash the “why” of it here.
There are three components that drive how responsive a page feels to an end user:
- Primary Page HTML response time
- Primary Page DOM parsing time
- Secondary Asset load time
The first component is driven by the server’s request processing time (DRP service time), the page’s HTML size, and the speed of the connection between your server and your end user’s computer.
The second component is driven by the size and complexity of the HTML DOM tree.
So, we have to look at file sizes, DOM complexity, number of files, cache headers, the speed of request handling on the server, and the network speed between the user and the server.
That’s a lot.
So where do we start?
First, let’s analyze where your weakest areas are.
Identify your most important pages. Typically this would include your home page, and your catalog navigation pages (assuming this is a commerce site). While the checkout flow is also critical, it’s much more likely to be constrained by the performance of the server-side checkout related processes.
Now that you have a list of pages to start with, you need to analyze them. The best set of tools to do this is thankfully free. Install the following, in order:
- Firefox – a great open source web browser
- Firebug – a web page debugging tool
- YSlow – an add-on to Firebug which provides performance specific information
Start Firefox, and if you’ve used it before, clear the caches before proceeding. Pull up your first page. At the bottom right of the Firefox window you will see the Firebug and YSlow buttons.
Click on the YSlow text. It will work some magic and then present a Performance Grade with a list of sub-section grades: