unefficient*, especially when putting actual video into gif format. most often those gifs are hideous (limited color palette etc) and huge (10+ MB for seconds of video), often either badly optimized (which would only make them look even more crunchy) or not optimized at all. gifs are just straightforwardly worse there (in quality and size). gifs are useful for having some graphics with transparency (if you don't mind crunchy one bit transparency), but there are much better formats (webp/webm, apng, etc) with much better 8-bit transparency too. seriously, people need to give it up and put video in a video format. like h264, which is gonna be widely compatible and likely hardware accelerated. (possibly performing better than huge gifs as well, hw accelerated or not)