Change your Mac display’s brightness
You can adjust the display’s brightness manually or automatically.
Use the brightness function keys
If the screen seems too light or too dark, you can adjust your display’s brightness.
On your Mac, press
or 
(or use the Control Strip).
Automatically adjust brightness
If your Mac has an ambient light sensor, choose Apple menu
in the sidebar. (You may need to scroll down.)Turn on “Automatically adjust brightness.”
If you don’t see the “Automatically adjust brightness” option, you can manually adjust the brightness.
Turning off auto-brightness may affect battery life, energy consumption, and long-term display performance.
Manually adjust brightness
On your Mac, choose Apple menu
Drag the Brightness slider to adjust the brightness of your display.
Depending on the type of display connected to your Mac, you may also see a Contrast slider that you can use to adjust the display’s contrast.
If your display is slow to reach full brightness
If your Mac display is slow to reach full brightness, try these solutions.
Give the display time to warm up.
Make sure the display brightness isn’t turned off. Press
to check or adjust the level of brightness.Turn on the ambient light sensor so your Mac can automatically adjust brightness based on current ambient lighting conditions. Choose Apple menu
These options appear only if your Mac has an ambient light sensor.
For specific information about the brightness of your display, check the documentation that came with your display.