Disable Auto-Brightness In an iOS 11 Device

In your iOS 11 device, ‘Auto-Brightness’ is turned on by default. Because of this, your screen automatically adjusts its brightness according to the light and ambiance of your location.
Although keeping ‘Auto-Brightness’ enabled is a good idea, for some people this screen behavior might be annoying, and they may want the brightness of their device’s screen to remain stable and static regardless of the light of the location.
If you are among those, here’s how you can disable ‘Auto-Brightness’ in your iPhone/iPad running iOS 11:
    Get to the General window
    Tap Settings > General. This opens the General window that allows you to customize general settings for your iOS 11 device.


    Get to the Display Accommodations window
    Tap Accessibility > Display Accommodations. This opens the Display Accommodations window that lets you adjust the display settings to best suit the ambiance your device is in.


    Disable Auto-Brightness

Tap the Auto-Brightness toggle button on the Display Accommodations window. This turns off the Auto-Brightness feature (if enabled) on your iOS 11 device.


Note: Unlike earlier iOS versions where the ‘Auto-Brightness’ toggle button was found in the ‘Display & Brightness’ window, the location of the button is changed in the newer iOS in order to make the settings look more organized and obvious.