When I was first learning to build web pages in 1998 the process of crushing images into virtual mosaics of compression artifacts was a required art. Now that Baud rate is all but forgotten it’s common to find sites with sliders full of 900x images, articles chock full of images, flash ads, etc. These site load fine with my highspeed cable modem or T1 at work (and look good too) but I can’t help and wonder if we are setting our expectations too high. Maybe I’m just having paranoid flashbacks of when a page would load one centimeter at a time (interlacing anyone?).
Although techniques like image preloading have helped the user experience at high bandwidth site are there any agreed upon performance guidelines for types of sites and connection bandwidth we have now in 2012?
I can list a few methods that I am using often.
Use sprites if you can. It will reduce the connection number. For example; you stored 150 icons/images in 8 image files. In this case, your browser will make just 8 connections instead of 150.
Use the right format for images. For example; Use jpg for photos, use png for mostly-geometrical images.
Again, to reduce connection number, combine your JS or CSS files in a single file.
Use different tools to measure the page and loading speed.
Do not load hidden images at the first place. http://www.wallbase.cc is a perfect example for this.
Use server side compression if you need it.
You can add more to these list. The logic is simple, reduce the bandwidth usage, reduce the connection count.