You can't post GIFs to Instagram. Most GIFs are very short (less than 3 secs) and are in a different file format than is accepted on Instagram. GIFstagram turns your GIFs into MP4 files that are of proper length & format so you can post them to Instagram.
Do you use GIFstagram: Convert GIFs to Insta-videos?
Recent GIFstagram: Convert GIFs to Insta-videos Launches
