Using the following link: https://stackoverflow.com/a/10616717/8166528, I can trim the whitespaces, however this method takes the first frame and trims it. So the animated gif will lose the remaining frames.
Is there a way to trim the whitespaces of an animated gif?
Added picture: https://i.sstatic.net/KMvK3.gif
I got it working using ImageMagick like @fmw42 suggested:
convert input.gif -trim +repage output.gif