Filming & Production
16:9 aspect ratio
Also called: sixteen by nine, widescreen, horizontal
16:9 means sixteen units of width for every nine of height, which covers 1920x1080, 2560x1440 and 3840x2160. YouTube's desktop and TV players are built around it, so a 16:9 upload fills the frame with nothing wasted at the sides. It also decides which library a video lands in. A square or vertical upload of up to three minutes can be classified as a Short, so exporting horizontal is what keeps a video in long-form. Cutting a vertical out of 16:9 footage discards about two thirds of the width, which is a reason to frame the original knowing the crop is coming.