App Store Screenshot Generator — Every iPhone & iPad Size

As of the current App Store Connect rules you need one 6.9-inch set (1320 × 2868) or a 6.7-inch set (1290 × 2796); Apple scales those down for smaller iPhones automatically. A 5.5-inch set (1242 × 2208) is only needed if you still support that hardware, and iPad sizes are required only when you ship an iPad build.

The frame keeps its device aspect ratio, and a capture from a different device gets cropped to fill it. Capture on the same device class you are exporting for — or switch the layout to "Screenshot only", which fits the image without cropping.

Yes. They are flattened, opaque and sized exactly to the accepted resolutions, which are the three things the upload validator checks. Apple additionally rejects screenshots showing an Android device, a price, or a "coming soon" claim — that is a content rule, not a format one.

Up to 10 per size, but the first two or three are what most people see in search results without swiping. Put the strongest value proposition in the first slide rather than a login screen.