Recently I noticed that there was a control named ToolkitScriptManager in the ASP.NET AJAX Control Toolkit and I was wondering how it was different from the regular ScriptManager. After reading this wonderful blogpost I came to know that ToolkitScriptManager will combine all the ASP.NET AJAX scripts by default. I decided to run a small test to see how exactly this effects performance and the results were quite impressive. I first created a simple page with the ScriptManager and the AJAX Calendar Extender control. Below is the screenshot from firebug:
As you can see from the above screenshot that with the ScriptManager control we are making 15 requests to the server, page size is 168.4kb and it takes 5.62 seconds to load this page. Now lets see how ToolScriptManager changes these numbers:
Now the you can see that the number of requests have come down to 7, page size is 124kb and it takes only 4.03 seconds to load this page.
All you need to do is just REPLACE
Conclusion: Imagine if you are saving 8 requests, 44kb of data and 1.59 seconds of load time on a page with a single AJAX Control. How much performance gain would you get on a page with update panels and many AJAX controls?