An adaptive UI means to adjust your content so that it fits well on any iOS device and that makes the best use of the available space.
In iOS, we use Size Class to deal with width and height which simpler and more generalized across multiple devices.
-There are only two options for an iOS size class, regular or compact. -Each iOS device has a default set of size classes that you can use as a guide when designing your interface.
Below are some of the size classes for devices in both portrait and landscape orientations.
| Device | Portrait (size class) | Landscape (size class) |
|---|---|---|
| iPad (all) | Vertical: Regular Horizontal: Regular |
Vertical: Regular Horizontal: Regular |
| iPhone X | Vertical: Regular Horizontal: Compact |
Vertical: Compact Horizontal: Compact |
| iPhone 8 Plus | Vertical: Regular Horizontal: Compact |
Vertical: Compact Horizontal: Regular |
| iPhone 8 | Vertical: Regular Horizontal: Compact |
Vertical: Compact Horizontal: Compact |
| iPhone 6 Plus | Vertical: Regular Horizontal: Compact |
Vertical: Compact Horizontal: Regular |
| iPhone 6 | Vertical: Regular Horizontal: Compact |
Vertical: Compact Horizontal: Compact |
| iPhone 5/5c/5s | Vertical: Regular Horizontal: Compact |
Vertical: Compact Horizontal: Compact |
| iPhone 4s | Vertical: Regular Horizontal: Compact |
Vertical: Compact Horizontal: Compact |
Read more: The Adaptive Model