Open Quick Settings or Control Center and move the brightness slider up
Go to Settings and increase Display or Screen brightness
Turn off Auto-Brightness or Adaptive Brightness
Disable Battery Saver or Low Power Mode
Switch to a brighter display mode or theme if available
Check if Night Light, Blue Light Filter, or True Tone is reducing brightness
Update display drivers or operating system if brightness controls are not working
Restart the device if the brightness setting is stuck
Clean the screen if it appears dim due to dirt or smudges
Increase brightness on an external monitor using its physical buttons or on-screen menu