Giff question

Hi everyone,

Could you please tell me how to make a giff file so that it shows a before and after when clicking on it. I must be missing something as I have created giffs before but I cant find the 'click' option anywhere.
Thanks

You can make .gif animations comparing two frames, but images can't be interactive in any shape or form. On all the sites I've ever seen mouse-over/click comparisons being done had javascript or flash to add the interactive element, in which case the format of the image can be anything, be it .jpeg or .png.
Unless this forum has some hidden option to allow you to make this kind of effect (never seen it), it's not going to be possible to do so, as it needs to be coded into the site itself.

A simpler way to go might be to slow down the Animation to about this speed:
An animated .gif file made with Photoshop