How to Remap the Fn Keys on macOS

All of the Fn keys on a Mac are mapped by default to perform specific functions that can be quickly accessible by users. For example, the F1 and F2 keys, when pressed, increase and decrease your screen’s brightness respectively. While some of the Fn keys and their associated functions are used regularly, some of them, like F3 – Expose view, might not be used that much, and it will be more useful to remap it to perform another function. Here we’ll show you how to remap the Fn keys on your macOS.

Also read: How to Add Options to macOS’s Services Menu

The first thing we need to do is to disable the default actions assigned to the Function keys. To do this:

1. Open System Preferences on your Mac.

2. Select Keyboard.

3. From the “Keyboard” menu, enable the option to “Use F1, F2, etc. keys as standard function keys.”

Once this option is enabled, you’ll see that the Fn keys, when pressed, will not perform the normal actions that are inscribed on them.

We’ll now assign our own custom shortcuts to them.

1. In the same window, open the “Shortcuts” tab.

2. Using the first and second tab, you can select a specific function you want and click on the keyboard shortcut in front of it to remap the function to a Fn key.

For example, if you want to use the F5 to turn “Do Not Disturb” on/off, simply click on the shortcut in front of it and press the F5 key on your keyboard.

Also read: How To Set a Do Not Disturb Keyboard Shortcut on Your Mac

It’s simple to assign one of the functions listed by default to a specific Fn key, but if you want to assign a custom function from an app’s menu, you can do so as follows:

1. In the “Shortcuts” section, select “App Shortcuts” from the left-hand pane and click on the “+” icon.

2.  Here you have a few options. Firstly, you can choose to create a shortcut that is common to all applications that offer the function. In this example, we’ll be creating a custom shortcut to enter “Full Screen” mode. Since I’d like that to happen in all applications, I’ll select “All Applications.” If you would like to create a shortcut for a specific app, you can choose that specific app from the list.

3.  We now need the exact function we want the keyboard shortcut to perform. Keep in mind that the shortcut will perform the specific function from the app menu, so we need to know the exact function name.

To check this, simply navigate to the app menu and note down the exact name of the function you want. Since we want our keyboard shortcut to enter full-screen mode on any app when pressed, we’ll find the option  from the app menu and take note of it.

The function name is “Enter Full Screen.” We’ll enter this in the “Menu Title” section of the System Preferences tab.

4. Simply specify the Fn key you want to use as the shortcut. You can specify any other keyboard key combinations as well.

Using the tutorials specified above, you can disable the default functions assigned to the Fn keys and replace them with custom functions of your own.

If you’d like to use a few of the default Fn key functions, while remapping a few for your custom shortcuts, you’ll need to install a third-party program to do so. We recommend using Karabiner. It is free and gets the job done.

In the application, you’ll find the option to remap the Fn keys to perform some different functions as well as work as another key. For any Fn key whose function you want to leave as is, don’t change any setting.

However, for the key you’d like to change, select the particular Fn key (for example, F8) from the list in front of it and use the guide mentioned above to assign a shortcut to it from your keyboard settings. Keep in mind, for this you’ll need to keep the “Use F1, F2, etc. keys as standard function keys” option disabled.

It is easy to remap the Fn keys in macOS. Did you find the guide useful? Let us know in the Comments section below.