Converting a large GIF image file to MP4 video is a modern approach, The end result file size will be smaller for no noticeable quality loss. It will then also be in a more web-friendly mode that can be segmented and playback be scrubbed.
Converting GIF to MP4 with FFmpeg in a simple command looks like this:
ffmpeg -i theinput.gif -movflags faststart -pix_fmt yuv420p -vf 'scale=trunc(iw/2)*2:trunc(ih/2)*2' theoutput.mp4
-movflags faststart
optimizes the keyframe segments for a quick starting playback.
-pix_fmt yuv420p
is the pixel format.
-vf 'scale=trunc(iw/2)*2:trunc(ih/2)*2'
Output needs dimensions which are divisible by 2, this ensures that.
This whole process is quick to complete as there is no active re-encoding of the data.