what determines file size?

what determines file size?
is it just the dimensions?
number of ‘nodes’ or what ever they are called - a cube has 8.
i am making small animated gifs with a clear background.
they are 200 x 200 files that end up as 40kb
50 images is 2000kb 2M
the gif ends up as a 1091 kb animated gif.
i would prefer they were a quarter of that or less.


i removed most of the verts - vertices i assume and the size did not change

GIF file size is dependent on image complexity. Large areas of solid colors compress well. Fine details, or shading don’t compress as well. Either way, Blender is not the tool to use for creating animated GIFs. Output from blender as PNGs, then take those into a 2D image editor to assemble the GIFs. I use GIMP, though there are, I’m sure, better programs for optimizing GIFs.

i know blender does not make gifs.
so i output the images from blender as PNGs as seen above, and make animated gifs from them.
i will be using blender - cos it is what I ‘know’ and it does do animations like things turning etc