Images in JPG, JPEG, PNG, GIF and WEBP formats and videos in MP4, MOV, AVI, MKV and WEBM are supported. You can upload up to 50 files at a time. Large videos are supported too, including files over 100MB: the system automatically uses optimized chunked upload and Meta's advanced upload, with no size-limit error. Very large videos can take Meta a few minutes to process, and the screen shows the progress of the media upload and ad creation in real time.