You can upload the following video file formats to combine in WeVideo: 3GP, 3GPP, AVI, DIVX, DV, FLV, M4V, MJPEG, MKV, MOD, MOV, MP4, MPEG, MPG, M2TS, MTS, MXF, OGV, WEBM, and WMV. If you're uploading audio files to merge as well, then WeVideo supports AIF, MP3, M4A, OGG, WAV, and WMA.