Favicon format GIF or ICO?

Question

Why use a GIF favicon? Is that for iPhone and iPad can read it?

Answer 1

GIF favicons are sometimes used so that they can be animated, but ICOs have wider browser support. If you are trying to make favicons specifically for iPhone/iPod Touch, you might want to take a look at this:

http://iboughtamac.com/2008/01/23/making-an-iphoneipod-touch-webclips-favicon/