When using an external keyboard, how can use a function key as a function key (e.g. F10) instead of Mac custom control button (e.g. mute)? The built-in keyboard contains an fn button, but I cannot find it in the external one.

  • When you say external, do you mean 3rd party? I'm confused because the recent Apple keyboards, even the small ones, come with a Fn key.
    – emgee
    Sep 18, 2009 at 5:33

10 Answers 10


The only way is to disable system-wide (that includes the notebook's keyboard) the custom control keys, and tell OS X that you just want to use it as normal F1-F12/F16 keys.

Go to System Preferences > Keyboard. Check the box that says "Use all F1, F2, etc. keys as standard function keys"

Screenshot of Keyboard Preferences in MacOS Catalina on a MacBook with a Touch Bar

If you are using a Mac keyboard, there should be a Fn key. On the latest Mac wired slim aluminium keyboard, it is around the home, page up, page down area. On the wireless slim keyboard, it is to the bottom left.

  • When taking a screenshot of a single window in OS X, pressing command shift 4 space will allow you to capture the single window with it's drop shadow, without any other apps in the background.
    – Josh Hunt
    Sep 18, 2009 at 8:42
  • @joshhunt nice screenshot :)
    – alex
    Sep 18, 2009 at 8:43
  • I am happy to report that you can safely enable this on the new 2016 macbook pros, and it works just fine for an external keyboard and leaves the touchbar intact!
    – chrismarx
    Jan 5, 2017 at 15:30
  • 6
    Unfortunately, this does not work on a Cherry KC 6000 Slim for Mac. Jul 29, 2021 at 12:10
  • 2
    This doesn't work for me...I already had that setting enabled and expected it to work as you have described, but it does so on my MacBook Pro's keyboard only. The external keyboard is still mapped in the default way, which is extremely annoying.
    – Kenny83
    Nov 10, 2022 at 21:43

Silly me. The fn button is below F13.


You can do that with Karabiner-Elements:

It allows you to configure the Fn keys per device. In this case, I set it to use the default keys when on the external keyboard:

enter image description here

  • 3
    Thanks, that totally worked for me using a windows keyboard on the mac. Not only i now can use the function keys for media controls as default osx does, but i also remapped all special keys like CTRL/ALT/WINDOWS key to match the layout of a mac keyboard. Great! Note: If you also use a "windows" mouse and need different scrolling directions for the mouse and your trackpad, check out "Scroll Reverser"
    – choise
    Apr 11, 2018 at 12:00
  • I use Spark and it helped me to remap some shortcuts in my Windows PC Keyboard to control some basic functions like the volume commands. A Con, the app was not maintained in a long period of time. Latest version 3.1b2 (470) can be found at shadowlab.org Dec 11, 2019 at 22:30

If you're using an external keyboard for a mac, check the external keyboard for a f-key lock button. On my logitech it is on the escape key.

(I just spent half an hour figuring it out!)

  • Thank you! I was struggling with this. Using Logitech MX Keys for Mac. Feb 3, 2023 at 11:46
  • Good one! For the Microsoft Designer Keyboard it is even more hidden: fn + caps lock locks and unlocks the function keys.
    – Wouter
    Aug 14, 2023 at 17:56

Interestingly for me Scroll lock (F14) worked as brightness down and Pause Break (F15) as brightness up on a USB PC keyboard.

  • Welcome to Superuser, your answer doesn't sound like a good answer, you have not shown enough concern to compose it properly. Just refer this link, superuser.com/help/how-to-answer. Jun 1, 2018 at 17:52

Also, you could try something like this utility.


If you are running Windows 7 under Boot Camp you can change in the Boot Camp control panel in your windows session. enter image description here


For me, I had to go to Keyboard > Keyboard Shortcuts > Function Keys and enable "Use F1, F2, etc. keys as standard function keys"

My system: M2 Macbook Pro, 2022 MacOS: Sonoma 14.1

enter image description here

enter image description here


I'm using Corsair K95 RGB USB keyboard, I too was figuring out how to use the brightness control on my Mac and then when I used the F14 and F15 keys, it all surprisingly worked out.


See if your keyboard manufacturer allows for this in their software. I installed Logi+ Options for my Logitech K380 and it allowed me to switch.

Logitech Panel

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