Whether you’re using a Windows PC or a Mac, your keyboard has all the standard function keys on top. These keys are assigned various functions by the computer’s operating system.

Some of the actions these keys perform are things like increasing and decreasing brightness levels, increasing and decreasing volume levels, opening certain functions and so on. On a Mac computer, these keys trigger some of the macOS default actions, such as opening the Mission Control view.

The problem here is that while some of these keys are used frequently, others remain unused simply because their functions aren’t as common. The best way to use these unused fn keys on Mac is to remap them.

Key remapping allows you to assign custom functions to keys. These keys will then perform the actions you assign them on your Mac.

Disable the default function key behavior

Before assigning any custom actions to your keys, the first thing you will want to do is disable the default actions of your keys. This will also disable useful keys but you can always use them by pressing and holding the key fn button on the keyboard. It will then make your keys perform the action printed on them.

Disabling function keys is easy on a Mac. Here’s how you do it:

Click the Apple logo in the upper left corner of your Mac screen and select System Preferences.

When the system preferences pane opens, find the option that says Keyboard and click on it to open it. The keyboard settings menu will open.

On the following screen, you will find some options that you can enable and disable. Find the option that says Use the F1, F2, etc. keys. as standard function keys and turn it on.

You have successfully disabled the default behavior of your fn keys.

Remap function keys

Now that the default function key actions are off, you can go ahead and assign custom actions to these keys. It’s easy enough to do this, and you don’t need a third party app to do the job.

You will use the same System Preferences panel to accomplish this task.

Launch System Preferences on your Mac and click Keyboard option.

When the keyboard pane opens, find and click on the tab that says Shortcuts on the top. It will allow you to customize the shortcuts on your machine.

The following screen will list all the keyboard shortcuts you have on your Mac. You can access various shortcuts by clicking on their category names in the left menu. Let’s assign one of these shortcuts to function keys.

Click on Screenshots in the left pane and click the link already assigned next to the first title it says Save the screen image as a file. Press one of the function keys on your keyboard and it will be assigned to the shortcut.

You don’t need to save any changes as it will be done automatically by macOS.

From now on, whenever you press the fn key specified above on your keyboard, it will take a screenshot instead of performing the normal action. You can assign any function key to any shortcut you find there.

Map function keys to perform specific actions

While the built-in Keyboard menu has many keyboard shortcuts to use and assign to the fn keys, it doesn’t have all the shortcuts. There are some shortcuts you may want to use by pressing the fn keys but those are not listed here.

One of the ways to have your custom shortcuts listed there is to add them to the list. The following shows how this is done:

Open the app for which you want to create a custom fn key action. For example, I open Google Chrome to create a keyboard shortcut fn to start an incognito window.

Click on the app menu items at the top and note the full name of the item you want to assign an fn key to. For me, it will be New incognito window.

In the following screen, set the options as follows and press To add.

Application – choose the app you want to create a shortcut for. If it’s a universal shortcut, choose All applications.
Menu title – this is the exact name of the object you noted earlier. Write it here.
Keyboard shortcut – press the fn key you want to assign to the action.

From now on, when you press the fn key you used above, it will perform the action you just entered in the menu title box. In my case, a new incognito window will open in Google Chrome.

Use a third party app to remap Fn keys on MacOS

macOS, by default, gives you many options to customize the behavior of your function keys. However, if you want even more power, you may need to use a third-party app.

Karabiner is one of the popular apps that helps you customize how various keyboard shortcuts work on your Mac computer. It allows you to create multiple profiles so that you can have one set of keyboard shortcuts in one profile and another set in one profile secondary.

There are many other features in the app that you may want to explore.

New uses for function keys

If you can’t think of any particular functions for your keys, you can assign some of the following functions to your keys. These are used by most Mac users.

• New tab browser
• New tab browser in disguise
• Screenshots
• Do not disturb mode
• Close app
• Hide and show the Dock

Feel free to use your creativity and imagination to make these keys work the way you want.

Conclusion

For most Mac users, the top row of keys remains unused as those aren’t the functions you might want to use from time to time. With remapping the fn keys, you can make those keys useful by letting them do the tasks you want.