This allows extra transparency to be added to the frames without letting the earlier frames show through the transparent parts. (The important options here are -U / -unoptimize and -disposal=previous, which together convert the animation into 'flipbook mode', where each frame is fully erased before drawing the next one. Where anim.gif and anim_trans.gif are the source and destination file names, and #ffffff is the hex code of the color you want to make transparent (here, pure white). You can do this with GIFsicle, using the following options: gifsicle -U -disposal=previous -transparent=' #ffffff' -O2 anim.gif > anim_trans.gif