Apps that support Dynamic Type will adjust to user’s preferred reading size. They can change the font size on their iPhone, iPad, and iPod touch. Here are two options to quickly test for different text sizes on iOS. Option 1: Text Size control in Control Center Customize Control Center to include Text Size as control. If you also want to test for Larger Accessibility Text Sizes, make sure to enable Larger Accessibility Sizes in Settings > Accessibility > Display & …