"gifv" is just an mpeg4 file that imgur serves a fallback gif for based on browser headers (mediacrush, gfycat have been doing the same thing for a while). The

"gifv" is just an mpeg4 file that imgur serves a fallback gif for based on browser headers (mediacrush, gfycat have been doing the same thing for a while). The "xng" here is a series of images animated/wrapped in SVG.