With iOS 11, Apple added a one-handed keyboard option to the iPhone. This should make it easier to type while holding a larger iPhone in a single hand. Both right-handed and left-handed keyboards are available.
Note that this one-handed keyboard only exists on 4.7- and 5.5-inch iPhones (like the iPhone 8 and 8 Plus)—it doesn’t exist on smaller iPhones like the SE, nor does it exist on the iPod Touch or iPad.
To quickly switch to the one-handed keyboard while typing, long-press the emoji key on the keyboard. When the pop-up menu appears, select either the left-handed or right-handed keyboard icons.
To return to the default two-handed keyboard, just tap the arrow button at the left or right side of the keyboard. You can also long-press the emoji key once again and tap the two-handed keyboard icon.
If you have multiple keyboards enabled, you’ll see a globe-shaped international keyboard key. Long-press the globe key instead of the emoji key to open the menu.
If you don’t see an emoji or globe key, this means you’ve disabled all additional keyboards, including the emoji keyboard. To re-enable the emoji keyboard, head to Settings > General > Keyboard > Keyboards > Add New Keyboard > Emoji. The emoji key will reappear on your keyboard.
You can also set the one-handed keyboard as your default keyboard, if you prefer it. To do so, head to Settings > General > Keyboard > One Handed Keyboard and select either “Left” for the left-handed keyboard or “Right” for the right-handed keyboard.
To restore the two-handed keyboard as your default keyboard, return here and select “Off”.
Third-party keyboards may also have a one-handed mode. For example, Google’s Gboard keyboard also allows you to select a “One-handed mode” option after you long-press on the globe option. So even if you don’t use Apple’s keyboard, give this a shot and see if your keyboard of choice has a similar option.