One of the things people don’t like is sitting in front of a screen that is not changing and wondering if their system has froze!
Now loading images can be used to let them know – the computer is not frozen something really good is coming – get ready for an awesome experience! Great thought but if the notice that builds up the anticipation is queued with the content of the great experience it does not go over very well — waiting to get a wait message not awesome.
Here is the trick, the method to pull it off.
First one needs to understand what is happening with the browser. The browser is being nice and only opening two streams to the site – it does not want to be a bandwidth or port hog.
Studies by Yahoo web development team show pages can actually download faster making parallel request. That is start loading everything at the same time. This can be accomplished without changing a thing in the browser, but rather by having another apparent server (or domain) to download the images from. Find the study here. It is required reading for web designers – the complete study for maximizing loading time is here
Some people may be thinking at this point, “I only have one server.” Let me put a smile on your face. http://www.server.com is one apparent server and http://server.com is apparent server number two. If you can add subdomains to your account. http://images.server.com would be a third apparent server.
There is a question of DNS request time – a very good question. For each domain name the browser must first make a request to determine the address of the domain name server. Then a request to that domain name server. These requests normally take a fraction of a second; lets give it a number 00:00:00.1 100 milli seconds may be typical. If the fast lane domain is say flicker then the two requests need to be made. If the page is downloaded from http://www.server.com and graphics from http://server.com the DNS server is the same – one request is needed to confirm the IP address is the same – the DNS server location is in the browser cache. If both http://www.server.com and http://server.com have already been called from another page on the site – both server locations exist in the browsers cache and no DNS request is made.