iPhone 7 vs iPhone 12

The iPhone 12 mini has a 5.4-inch screen, while the iPhone 7 has a 4.7-inch screen

Please take a look at the following link for a tool to compare these devices.

https://www.apple.com/uk/iphone/compare/?device1=iphone7&device2=iphone12mini&device3=iphone12

The iPhone 12 mini is slightly smaller than the iPhone 7, though it does have a larger screen.

The regular iPhone 12 is a bit larger than the iPhone 7.