Is flashlight on the back of your iPhone too bright? Here’s how to reduce or change the flashlight brightness level on iPhones with current iOS 13 (as of March 2020).
On your iPhone, go to the Control Center (swipe down from the upper-right corner of the screen on the iPhone 11, 11 Pro, Pro Max, X, XS, XS Max, or XR; swipe from the bottom up on older iPhone models).
Tap and hold the flashlight icon to reveal the flashlight brightness adjustment screen.
On the flashlight brightness adjustment screen you can select one of the four levels of flashlight brightness by tapping on the desired level or by swiping up & down across the bars. Tapping on the lowest bar turns the flashlight off.
Your iPhone will remember your brightness level choice even after you turn off the flashlight. The choice will be remembered until you change the level again or reboot the iPhone.