Why do I need the Fn key and how to use it

What is this key

Fn, or Function, is a special modifier key that enhances the keyboard of a laptop or computer. It changes the purpose of the standard buttons and allows you to perform additional actions with their help.

Why do I need the Fn key

Fn came along with the proliferation of compact keyboards and is most often used to add missing keys to laptops where a full set simply does not fit. For example, pressing Fn in combination with PageUp or PageDown can make the OS think that Home and End have been pressed, although physically these buttons are not present.

In addition, the modifier key enhances the usability of your notebook by adjusting screen brightness, keyboard volume, and backlighting, as well as disabling and enabling wireless modules, the touchpad, or putting the computer into sleep mode.

On some devices, Fn + NumLock can turn the J, K, L, U, I, O, 7, 8, and 9 keys into a numeric keypad for quick number entry when working with tables.

Where is the Fn key

The location of the Fn key differs depending on the product model. Usually it is on the far left in the bottom row next to Ctrl. Sometimes Fn is in the place of Ctrl, while the latter is in the lower left corner of the keyboard.

How to use the Fn key

Pressing Fn separately does nothing. The modifier works only in conjunction with other buttons and only with those that have a dual purpose. For example, the top row of function keys F1 – F12, when pressed normally, performs its usual functions: F1 opens help, F5 refreshes the page, and so on.

But if you click on them while holding Fn, then depending on the manufacturer of the device, the assignment of the keys will change. Let's say on a Microsoft Surface keyboard, F1 will mute, and F5 will start playback in the player.

How to disable the Fn key

Depending on the default setting, alternate key actions sometimes work without pressing Fn, and when combined with a modifier will invoke basic functions. If this is inconvenient for you, you can switch the Fn operating mode and do the opposite.

In some models of laptops and computers, this option is available in the OS settings and proprietary utilities of the manufacturers. For example, to disable the Fn key on a Mac, just go to system preferences, open the "Keyboard" section and check the box "Use function keys F1, F2, etc. as standard."

Also, some devices have an F ‑ Lock key (also FnLock or FnLk). Typically, it is combined with Escape (Esc) and may have a lock icon. When you press it in combination with the Fn button, the commands of the function keys will change from alternative to basic.

Unfortunately, F ‑ Lock is quite rare, and usually the key mode is switched in the BIOS.

To do this, go to BIOS and open the System Configuration or Advanced section.
Find the Action Keys Mode parameter, which may also be called Function Key Behavior, Function Keys Mode, or HotKey Mode.
It will have one of two values selected, which have different names. Just change it to the opposite: Enabled to Disabled, Function Key to Multimedia Key, and so on.
Press F10 to save the settings and confirm the reboot.

How to swap Fn and Ctrl places

If you find it annoying that the Fn key is in the Ctrl position in the lower left corner of the keyboard, you can try swapping them. True, this opportunity is not available everywhere. So, it is definitely in Lenovo laptops.

To reassign the keys, go to the BIOS, open the Config → Keyboard / Mouse section and set the Fn and Ctrl Key Swap parameter to Enabled. Press F10 to save settings and restart your computer.