What is the "Fn" or "Function" key on a keyboard?

Confused by that "Fn" key on your keyboard? 'Fn' is actually short for 'function' and lets you access a range of alternative functions for the other keys on your keyboard. Today we are going to find out how to use it.

What is the Fn key?

The Fn key was originally created due to lack of space on previous keyboards. Instead of adding more keys, they received more functions.

As an example of one of its uses, the Fn key on some laptops allows you to adjust the brightness of the screen when pressed in conjunction with another key. Think of it as a button similar to the Shift key. Depending on your device, Fn may also allow you to:

  • Adjust the volume up and down.
  • Disable your laptop's internal speaker.
  • Increase or decrease monitor brightness or contrast.
  • Activate sleep mode.
  • Put your laptop into hibernation.
  • Eject a CD/DVD.
  • Lock the keypad.

The key is used differently depending on the operating system, but Macs, Windows, and even Chromebooks all have a version of the Fn key.

Coming Soon: 47 Keyboard Shortcuts That Work in All Web Browsers

Where is the Fn key on my keyboard?

It depends. On Apple laptops and PCs, the Fn key is usually found in the lower left corner of the keyboard next to the Ctrl key.

Chromebooks, on the other hand, may not even have one. Some do, however, and it's located near the spacebar.

On Macbook laptops, you will almost always find the Fn key on the bottom row of the keyboard. Full-size Apple keyboards may have it next to the "delete" key. On wireless Apple Magic Keyboards, the key is located in the lower left corner.

If your computer doesn't have an Fn key, your keyboard probably doesn't have any of these alternative functions. You might want to upgrade to a keyboard that lets you use them.

Coming soon: The 10 best wireless keyboards

How does the Fn key work?

The use of the Fn key varies depending on the operating system you are using. It is used in the same way as other modifier keys like "shift", often in conjunction with the F1-F12 (function) keys at the top of your keyboard.

Functions are generally designated by the same symbols, even on all operating systems. A sun symbol, for example, is typically used to indicate screen brightness. A half-moon generally indicates that the computer is sleeping. etc

Function keys at the top of a Mac keyboard

Note: The Fn key will not always work the same with peripherals as it does with the main computer. For example, Fn and the brightness key may not adjust the brightness on an external monitor.

the Windows

On a Windows PC, the special functions of F1-F12 can be accessed by holding down the Fn key and then pressing one of the function keys. This can include muting the sound or adjusting the screen brightness.

So, to use the Fn key on a PC:

  1. Hold down the Fn key.
  2. Simultaneously press the function key you want to use.

Some keyboards have an Fn key that lights up when pressed. If you have a keyboard like this, check to see if the light is on (if the key has been activated) before pressing the secondary function key.


On a Mac computer, the F1-F12 keys will perform these special functions by default. F11 and F12, for example, will increase or decrease the volume of the computer without you having to press the Fn key first. Pressing the Fn key followed by one of the F1-F12 keys will cause a secondary action specific to the application you are currently using.

Some Fn keys will be color coded to correspond to certain functions. On these keyboards, you will see "fn" in two different colors on the Fn key. These keypads will have two sets of secondary functions, also color coded. If your Fn key had "fn" printed in red and blue, for example, pressing Fn and a red key would be a different function than Fn and a blue key.

How to Use the Top Row of Your Mac Keyboard as Normal Function Keys
Coming Soon How to Use the Top Row of Your Mac Keyboard as Normal Function Keys

Most computers allow you to customize the function keys to some degree. On a Macbook, you can choose whether the F1-F12 keys use their default special keys or not. Some keyboards give you the option to disable the Fn key using “fn lock”.