Which aspect ratios are accepted for image assets in app campaigns?

In an App campaign, the accepted aspect ratios for image assets are 1:1, 1.91:1, and 4:5 because these specific dimensions ensure your ads can be automatically formatted and displayed across all Google properties, including the Search Network, YouTube, and the Google Display Network. The 1:1 (square) ratio is essential for standard display and Play Store placements, while 1.91:1 (landscape) and 4:5 (portrait) allow for high-impact visibility in specialized feeds and mobile-centric environments. Providing assets in all three of these ratios is a core creative best practice, as it maximizes the system's ability to participate in more auctions and serve the most visually appealing ad format to a potential user regardless of the device or platform they are using.