I tried a variety of different video file formats and it seems to playback all of them fine (MOV, MKV, MP4, GP3). The one format it had problems with is AVI: the video is clear but I got an dialog from the projector stating, "Cannot play audio format" (or something to that effect). I'm sticking with MKV format for when I rip DVD/Blurays to digital video for playback from USB drive.
Postscript: not sure why but the video I no uploaded from my iPhone 9 got really pixelated (video compression courtesy of Amazon?). That does NOT reflect the quality of the projector's image: it's __way__ clearer than that! Still recommend this projector!