In my <head> section i do have this line of code: <script type="text/javascript" src="/js/prototype.js"></script> <script type="text/javascript" src="/js/scriptaculous.js"></script> Code (markup): Its pretty obvious that I need ajax in my site but when I removed that code my site loads faster so I end up choosing not to use it. I really like to use ajax but how to use it without affecting my site load time?
make sure you have a content type handler (via httpd.conf or .htaccess) that deflates .js files - this enables gzip compression and reduces size to client, hence reducing the time it takes to download. however, sometimes the reverse effect is noticed - when the server is lagged / cpus are under heavy load, it may add to the time it takes to prep the data. anyway - there are a few other issues known to cause this. for example, having inline js blocks can cause a huge delay, here's an extract from google labs' keynote on web performance at AJAX Experience this summer: in other words, you can't really tell why something is performing slowly unless you look at the whole picture and profile it. it could also be the domready / onload being messed up / firing late. to profile speed - install firebug, then YSlow for firebug and check components. you can then also profile the javascript itself to see if a particular function is not being too slow. good luck