How can I toggle the Fn (function) key?

Question

Is there a way to toggle the Fn key? I'd like to be able to toggle it so I don't have to press Fn+F12 to raise the volume, for example.

I'm running Ubuntu 16.04.1 LTS on an Asus D550C.

Solution 1

As far as I know, the Fn key does not get detected by the OS but modifies your other keys on a firmware level. That means you can neither retrieve nor control the state of the Fn key from Ubuntu.

---

What you could do instead is to change the keyboard shortcut for increasing/decreasing audio volume to an alternative key combination instead of the Fn-modified special key.

Open System Settings → Keyboard and go to the Shortcuts tab. In the list on the left side, select Sound and Media.

After clicking on an entry in the list on the right side (in your case you want to edit Volume up and Volume down), you can press a combination of keys you want to assign to this shortcut. Esc cancels the editing and ← Backspace disables the shortcut.

Solution 2

For some computer models, to toggle F1 .. F12 keys use media functions or to be the "F" keys press Fn + Esc .

Solution 3

If you have an Apple keyboard and want the function keys to act like F1-F12 by default (disable Fn default behavior) give the following command in terminal:

echo 2 | sudo tee /sys/module/hid_apple/parameters/fnmode

from here: https://help.ubuntu.com/community/AppleKeyboard#Change_Function_Key_behavior

Solution 4

Press Fn+Fn Lock. It will toggle between Enable and Disable.

Solution 5

My laptop has a Fn Lock key which is useful, except when it's been pressed by accident. Then pressing F5 in Firefox doesn't reload the page; it switches off the touch pad. I now know what it is but it had me totally bamboozled having to reboot or logout to get the touch pad back working.

View more solutions

Comments

[roeland]

This could be an option in your bios.

[Frank Nocke]

Should be in your BIOS → config → is usually either „F1-F12 as Primary Function: On“ or something like „HotKey Mode“ (change from enabled to disabled or vice versa)

[WinEunuuchs2Unix]

Great tip because you can use one hand.

[Jithin Pavithran]

Works with some laptops like Lenovo Thinkpad series.

[Jujhar Singh]

Works great on my Lenovo T460 and Dell XPS 15

[TheCommoner282]

Works with Dell Inspirion 5000 series. Thank you Andrey

[MathKid]

With the Microsoft Natural Ergonomic Keyboard 4000 this key is called F lock and is located on the top row next to F12. Pressing it toggles a green LED at the bottom of the keyboard with an F below it. If the LED is off, the function keys don't work.

[Craig Wilcox]

Fn + Esc Works like a charm on my DELL Inspiron 15 ~ Thanks! Not sure what 'media functions' is/means

[ftassi]

it seems not to be working on macbook pro 11,4

[Eric Dela Cruz]

Works for a MBP 6,1 (2010 17")

[emi]

Confirmed for Kloner Bluetooth Keyboard KTB0025.

[Liam Baker]

This doesn't work on all laptop brands...

[Igor Rodriguez]

In the HP Zbook G5 the shortcut is Fn + Shift support.hp.com/us-en/document/c02035108

[n1k31t4]

Worked on HP laptop with Ubuntu 18.04 using an Apple keyboard.

[Manikandaraj Srinivasan]

This works on my Dell Latitude. And this should have been the accepted answer IMHO.

[Ezekiel Victor]

Worked on Ubuntu 18 Ubuntu desktop w/ Apple keyboard

[Willi Mentzel]

doesn't work on Dell XPS 9570 and Ubuntu 20.04 LTS :(

[Vignesh]

This worked on Dell Vostro series laptop, I was confused what the hell happened doing this reversed the keys back to normal

[Anton Matosov]

Worked for Ubuntu/PopOS 20.04 and doesn't even require reboot

[foo]

is "Fn Lock" supposed to be a separate key? If so, where could it be found?

[aderchox]

Doesn't work on my HP laptop Ubuntu 20.04

[Tiana987642]

Work with feker machinist 01, Ubuntu 18.04, no reboot :)

[Akshay Alva]

@foo its your Escape(Esc) key, in the top left corner.

[A. Steenbergen]

How can I make this work across reboots?

[kumetix]

Lovely! works on Dell XPS 15, Ubuntu 18.04.5

[Zanna]

@A.Steenbergen you can probably use sysfsutils - see my answer here for an example (for a different setting - adjust as needed).

[Edgar Ramírez Mondragón]

Worked on my Dell G7 with Ubuntu 20.04

[Borislav Gizdov]

Great, worked on ubuntu 20.04 with Keychron K3 keyboard (Mac mode)

[mwieczorek]

Tip of the day! I recently bought a new MSI Prestige that swaps the F keys with volume, keyboard backlight, etc. I'm a developer, so I always need the original F key functionality. I wish I could upvote this answer twice.

[veritas1]

Thanks! Got a new Vamillo (VA88M) keyboard, using with PopOS, and the fact that media controls were the default action was bugging me.

[王子1986]

works for manjaro system as well

[Kakiz]

That was very helpful, i switched from media key to function key at BIOS

[MRule]

Doesn't seem to work on LenovoP50

[MRule]

In that case, this is the same as /u/Andrew's answer --- and it doesn't work on all systems.

[Kalizi]

Thank you, this saved my day! If someone gets here, this will switch the function keys to the default behaviour, keeping multimedia working with FN key!

[KaKi87]

Worked on Ubuntu 21.10 using a Matias keyboard, thanks.

[Arpad Horvath]

I've just realized that there is a small FnLk written on my Thinkpad X250s Escape button. Easier to find out next time.

[Admin]

Worked like a charm on latest Gnome! First time I see gnome changing my Fn .. unsure why but thanks

[Admin]

This helped me as well: I have a mechanical keyboard from a chinese manufacturer - Hello Gonass which has an fn key. Works fine on windows but the fn keys don't work on Linux. echo 2 | sudo tee /sys/module/hid_apple/parameters/fnmode makes it work again.

[Admin]

Brightness up and down?

[Admin]

On HP laptops the fn lock key is the left shift key.