Gradient Circle Format Test Review

Best Image Quality:   PNG 24
Worst Image Quality:   GIF Restrictive

Smallest File Size:   JPEG Low
Largest File Size:   PNG 24

Which image has the best balance of quality and file size? Why?
               The PNG-8 128 Dithered had the best file size for quality. The quality was comparable to the PNG 24 (you can barely notice the difference) and it has a 9 KB file size, which is about average.