Most video content you see on TV, as well as computers and mobile devices, is displayed in this aspect ratio. In fact, the standard aspect ratio for videos is actually 16:9, also known as the widescreen aspect ratio. We’ll also go over which aspect ratio works best for particular social media platforms.įor instance, TikTok requires videos with a 9:16 aspect ratio, and for YouTube, it’s 16:9. In this article, we’ll show you how to change the aspect ratio using iMovie on different devices.