For which platform are 9:16 aspect ratio videos primarily used?

The 9:16 aspect ratio is primarily associated with vertical videos, which are commonly used in stories format across various social media platforms. Facebook Stories, along with Instagram Stories, are designed for full-screen viewing on mobile devices, making the 9:16 aspect ratio ideal. This format allows videos to fill the entire screen, maximizing engagement and visual impact for viewers.

In contrast, other platforms like the Facebook feed or Instagram feed typically utilize a landscape format that may be closer to a 16:9 ratio or similar square formats. These feeds can accommodate different types of media, but they do not specifically cater to the vertical video format that 9:16 represents, which is tailored for quick, engaging and often ephemeral content typical of stories. Facebook search results also do not emphasize a specific video format, focusing instead on presenting content in a more traditional feed format. Thus, the primary use of the 9:16 aspect ratio aligns most closely with Facebook Stories.