convert every file from jpg to gif in terminal

I have work with find before to find all specific files in a folder and subfolder and do something about it

for example I did use

find /folder/ -name '*.txt' -exec chmod 666 {} \; 

this code to easy change write access to every text file in the folder.

Now I was going to try to convert every jpg(even JPG) to gif in the same way but not sure if that is so easy. When I do trying with the convert command tools it want to have a inputfilename and output filename but I do not think find give that so maybe find is not the right Tools to use?