How to Fix Display Brightness Not Working on Mac

Is your display brightness not working on Mac?

With every new version of the Mac, Apple keeps adding exceptional display features that we can modify according to our needs. One such feature is the brightness, which is an essential component for everyday usage of Mac.

However, many users have complained about their display brightness not working on Mac. There are times when you increase or decrease the screen brightness, but the controls simply fail to work. This can be due to background system issues, disabled automatic brightness, etc.

Whatever the cause is, various methods can help you resolve this issue. We’ve done a fair amount of research and included in this article the main solutions that can fix the brightness issues on Mac.

So, let’s continue!

1. Restart Mac. 

The first and foremost method that works to fix various common Mac issues is restarting it. By doing that, you’re giving your device a fresh start, removing all the background processes that may be causing trouble. Alongside this, it will eliminate any temporary bugs behind the brightness issue. 

Here’s how to do it: 

  1. Go to the Apple menu from the menu bar. 
  2. Now, click on Restart
restart mac

Once your Mac restarts, you should be able to change the display brightness. 

2. Check Display Settings. 

Mac has an option that automatically adjusts the display brightness according to the surrounding lighting. So, if you have this option disabled, it may be the cause behind the display brightness not working on Mac. 

To fix it, ensure the Automatically Adjust Brightness option is enabled by heading over to display settings. Here’s how:

  1. Start by pressing Command + Space bar keys from your Mac’s keyboard to access Spotlight Search. 
  2. Enter ‘System Preferences’ in the text field and press the Return key. Alternatively, click on the Apple menu and select System Preferences.
Display Brightness Not Working on Mac
  1. Next, choose Displays from your screen’s lower-left corner. 
displays in system preferences
  1. From the right side, locate Brightness and check whether the Automatically adjust brightness option under it is checked or not. If not, check the box next to it to enable Mac to increase or decrease the display brightness automatically. 
Display Brightness Not Working on Mac
  1. You may also use the slider next to Brightness to adjust your Mac’s brightness manually.

3. Check Keyboard Settings. 

Another shortcut to dim or brighten your Mac’s display is by using the F1 and F2 keys. However, if you’ve accidentally or deliberately changed the keyboard settings to use them as Standard Function Keys, they won’t work to change the brightness levels. 

So, if the display brightness is not working on Mac, consider checking the keyboard settings. To do so, below are the steps you must follow:

  1. Click on the Apple menu from the top-left corner and choose System Preferences. You may also head to the Spotlight Search by pressing Command + Space bar keys. From there, type ‘System Preferences’ in the search bar and select the same from the search results.
  2. After that, click on Keyboard
keyboard in system preferences mac
  1. Ensure you’re on the Keyboard tab from the top, look for Use F1, F2, etc. keys as standard function keys option and uncheck the box next to it.
Display Brightness Not Working on Mac

After you’re done, use the F1 and F2 keys to check whether you can change the display brightness. If unsuccessful, move to the next method from this guide to fix your issue. 

4. Disable Slightly Dim Display. 

If you cannot change the display brightness when your Mac is on charge, it may be because you’ve enabled the slightly dim display while charging. Although this feature improves and saves your Mac’s battery, turning it on might result in the display brightness not working on the Mac problem. 

So, head to the battery settings on your Mac to resolve the problem. Here’s what you need to do: 

  1. From the menu bar, click on the battery icon
  2. Then, choose Battery Preferences from the options that appear. 
battery preferences
  1. This will open a new window. From there, uncheck the box present next to Slightly dim the display while on battery power
Display Brightness Not Working on Mac

The display brightness should be working fine after this method. If not, consider resetting SMC by following the next method. 

5. Reset SMC. 

It’s time to move towards some advanced options if you’re still unable to fix the display brightness not working on Mac, and resetting SMC would be a good place to start. 

System Management Controller or SMC is a powerful chip containing all the necessary information regarding your Mac’s hardware components. Resetting it will allow your system to restore the default settings of various functions, including brightness.

Follow the steps below to do so:

  1. Begin by pressing and holding the Power button, allowing your Mac to shut down. 
  2. Wait for a while. 
  3. Now, press and hold the Shift + Control + left Option keys while simultaneously pressing the Power button for around 10 seconds. 
reset SMC on mac
  1.  Release all the keys. You will see the Apple logo indicating that your Mac is turning on. 
  2. Lastly, see if you can change your Mac’s brightness levels.  

Keep in mind that you can only reset SMC in Intel-based Macs. 

6. Reset NVRAM. 

Along with various other settings, the display settings of your Mac are stored in NVRAM or Non-Volatile Random Access Memory. So, if resetting the SMC did not solve the brightness issue, try resetting the NVRAM. 

Here’s how: 

  1. Press and hold the Power button to shut down your device. 
  2. After that, restart your Mac by pressing and holding the Power button again. 
  3. As it turns on, press and hold the Command + Option + R + P keys from the keyboard for at least 20 seconds. 
reset nvram on mac
  1. Finally, release all the keys once you see an Apple logo on your screen. 

Remember that you can only perform the NVRAM reset if you’re using an Intel-based Mac. 

7. Update macOS. 

Removing temporary bugs and glitches is essential in resolving various Mac issues. Apart from releasing new features, macOS updates allow you to eliminate bugs within the system. Therefore, you should check for any software updates from time to time and install them if there’s one available. 

Follow the steps below to update your Mac:

  1. Select the Apple menu from the menu bar and click on About This Mac
Display Brightness Not Working on Mac
  1. Next, choose Software Update
mac software update
  1. If there’s a pending update, click on Download and Install
  2. The update will take some time to install. Once done, your display brightness issue should be resolved. 

This concludes our guide on how to fix display brightness not working on Mac. If you have any thoughts, suggestions, or queries regarding this topic, use the comment section below. We’ll get back to you in no time. 

If this guide helped you, please share it. 😊


  • Aimen Choudhry

    Aimen Choudhry is an architecture student who has always been fascinated by science. She now finds her therapy researching and writing about the latest technology and the issues that come alongside. Otherwise, you’ll find her playing video games, listening to music, or watching fantasy/sci-fi movies.

1 comment
  1. What do you do when the entire brightness settings section is missing from that part of the settings screen? I’ve reset the OS and completely reinstalled. Backlight works perfectly when booting to Windows.

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