What Are F5 and F6 Keys on Mac

The function or F keys on our keyboard often go unused because it is unclear to many what they may be used for. The F5 and F6 keys on your Mac are two keys that you may have yet to use and may be unaware of what they do. They both have to do with keyboard brightness.

F5 decreases the brightness of your Mac’s backlit keyboard.

F6 increases the brightness of your Mac’s backlit keyboard.

My name is Eric, and I have used a variety of computers over the past 40 years. Most keyboards have not changed a whole lot, but function keys are something that can be a bit different from system to system. Mac’s function keys have a standard configuration with a specific use for the F5 and F6 keys.

I have shown you what they are for above, but keep reading if you want to hear a little more detail about them, how to use them, and whether you can change the functionality of the F5 and F6 keys as well as other function keys.

The F5 and F6 keys and How to Use Them

So, we know that the F5 key decreases the keyboard brightness, and the F6 increases it. That’s fairly straightforward, but if you are not a frequent user of function keys, you may need a little help with how to use them. No worries, I will show you how to do that here.

The function keys on a Macbook and most other Mac keyboards are located along the top row of keys. In newer MacBooks, you will have a Touch Bar that digitally simulates the function keys and is located just above the top row of keys. 

The function keys have a default configuration, and each of them is already assigned, such as the F5 and F6 keys, but they are configurable, so they can be set up to do other things. We will discuss this more in the next section.

To use the function keys for the standard built-in system functions, you must hold down the Fn key and press the Function key you wish to use. To decrease the keyboard lighting, you would hold down the Fn key and press the F5 key. 

If you do not press and hold down the Fn key, the Function keys are assigned according to the specific application active on your screen and not the system-wide function they are assigned to. 

You can change this in your config settings if you do not want to hold down the Fn key to use the system-wide actions of the function keys. You can use the following steps to change the touch bar on newer MacBooks.

Step 1: Open System Settings.

From the Apple menu, select System Settings.

Step 2: Select Keyboard.

In the left-side panel, select the Keyboard settings.

Step 3: Click on Touch Bar Settings

Step 4: Set Touch Bar shows setting.

For the Touch Bar shows setting, select Expanded Control Strip.

Step 5: Click Done

Click Done to save the changes. You should now see the icons displayed on the function keys, and there will be no need to press the Fn key when using them.

Configuring the F5 and F6 Keys to Do Something Else

Your Mac’s function keys can be configured to perform different actions. If you do not want the F5 and F6 keys to adjust the keyboard brightness, it is possible to configure them to do other things. You can configure the others as well.

I will not go into detail here about configuring function keys on all keyboards, but if you have a MacBook with a touch bar, configuring it is easy, and you can do so with the following steps.

Step 1: Open System Settings.

From the Apple menu, click on System Settings.

Step 2: Select Keyboard

In the left side panel, select the Keyboard settings.

Step 3: Click on Touch Bar settings.

Step 4: Click on Customize Control Strip.

Step 5: Drag the functions you wish to use from the screen down to your touch bar.

You can drag them directly to the bottom of the screen, and they will appear on the Touch Bar.

Step 6: Click on the Done button to save the changes.


Below are a few common questions about the F5 and F6 function keys.

What is keyboard backlighting?

Keyboard backlighting is the light you see in your keys, especially in low-light situations. Most newer MacBooks have keyboard backlighting, and some external keyboards have it. Some older MacBooks and external keyboards do not support this feature.

Why would I need to adjust the brightness of my backlit keyboard?

This feature is meant to help you in low-light situations so that you can see the keys on your keyboard. If they are not bright enough, you may need to brighten them. If you are in a place with plenty of light, you may want to dim them to save battery power. 

Why don’t the F5 and F6 keys work for my Macbook?

If your F5 and F6 keys do not affect the keyboard brightness, it is likely due to a setting in your configuration. You can set the keyboard so the brightness is not adjustable in low light. You can go to System Settings and then Keyboard and enable the ability to adjust the brightness in low light if you wish to do so.


The F5 and F6 keys on your Mac are generally used to adjust keyboard brightness. You will need to press the Fn key first, then the F5 to decrease or the F6 to increase the brightness. These keys are configurable, so you can change them if you want.

The information above has helped you with the function of your F5 and F6 keys. As usual, let me know if you have any questions or comments.

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