Andy King over at www.websiteoptimization.com has developed a pretty convincing case for why the use of PNG (Portable Network Graphics) images over GIFs to boost Web site performance. They maintain the clarity of GIFs with smaller file sizes and have a number of other benefits. Check out Andy’s complete analysis:
http://www.websiteoptimization.com/speed/tweak/png/
One other benefit of PNG files is that they can be HTTP compressed (or compressed further) as well at the Web server with none of the issues with associated with larger file sizes when you try to compress a GIF or JPEG. Given browser issues, we have revised httpZip’s default settings to include compression of PNG responses for Internet Explorer 7 clients… they can handle compression flawlessly for PNGs, per our testing at Port80 Labs. Bitmaps have also always been good HTTP compression candidates…
Have a good one,
Port80