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.

score 320 · Answer 1 · edited Sep 19 '21 at 12:54

320

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

edited Sep 19 '21 at 12:54

Quasímodo

2,104

answered Jan 11 '17 at 23:41

Andrew

3,327

score 89 · Answer 2 · edited Nov 14 '20 at 14:25

89

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

edited Nov 14 '20 at 14:25

Zanna

72,312

answered Jul 03 '19 at 17:38

zardosht

1,241

score 25 · Answer 3 · edited Nov 08 '19 at 08:33

25

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

edited Nov 08 '19 at 08:33

Eliah Kagan

119,640

answered Nov 08 '19 at 06:39

Atul6.Singh

367

score 25 · Accepted Answer · answered Aug 29 '16 at 21:12

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.

score 17 · Answer 5 · edited Nov 12 '17 at 05:00

17

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.

edited Nov 12 '17 at 05:00

wjandrea

14,504

answered Nov 12 '17 at 04:39

rhubarbdog

422
1
4
11

score 7 · Answer 6 · edited Nov 14 '20 at 14:28

7

On HP probook 450, left shift has fn lock, so fn+leftShift locks it.

edited Nov 14 '20 at 14:28

Zanna

72,312

answered Nov 05 '20 at 20:47

HasJ Core

71

score 6 · Answer 7 · edited Mar 24 '19 at 08:36

6

Press Fn+Num Lock to disable it.

edited Mar 24 '19 at 08:36

zx485

2,865

answered Mar 23 '19 at 20:03

Qu3d45

69
1
2

score 3 · Answer 8 · edited Jul 31 '20 at 13:16

3

Look in the BIOS. For Acer laptop I can choose the toggle on Fn touch in it.

edited Jul 31 '20 at 13:16

Eliah Kagan

119,640

answered Jul 30 '20 at 14:12

TikTaZ

141

score 1 · Answer 9 · answered Dec 19 '20 at 20:56

In addition to zardosht answer above as I cannot comment yet.

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

To make this work after reboots I followed Zanna's link to add in sysfutils Ubuntu 17.04 Macbook Pro Tilde key Fix

Added this in the last line to end of file

module/hid_apple/parameters/fnmode = 2

save, reboot and should be working.

Thanks!

score 1 · Answer 10 · answered Mar 28 '22 at 20:48

1

On some Keyboard, the left shift is the fn lock key. Press fn+left shift to toggle

answered Mar 28 '22 at 20:48

Swaleh Matongwa

111

score 1 · Answer 11 · answered Jan 04 '23 at 04:21

1

Ubuntu 20.04
From BIOS (if fn + Esc is not work)

Go to the Bios
Navigate to the Main tab
Look for the Function Key Behaviour setting and set Function Key instead of the Media Key option.

answered Jan 04 '23 at 04:21

johirpro

111

score 0 · Answer 12 · answered Dec 22 '22 at 19:22

0

On microsoft keyboard with trackpad:

[Fn-Caps]

answered Dec 22 '22 at 19:22

Joao Polo

101

score 0 · Answer 13 · answered Jan 23 '24 at 22:26

0

On Huawei laptops, press fn key once. This will toggle the behaviour. On some models, the "disabled" behaviour will be indicated with a LED light on.

answered Jan 23 '24 at 22:26

myrs

311

score 0 · Answer 14 · answered May 04 '24 at 12:11

0

I have a ThinkPad T480 with a Keychrone K3 and what worked for me was:

echo 1 | sudo tee /sys/module/hid_apple/parameters/fnmode

The default was 3, the 2 option doesn't work, but the 1 is working well.

answered May 04 '24 at 12:11

Ender Bonnet

1

score 0 · Answer 15 · answered Jul 17 '24 at 07:37

0

Restart the system and go to UEFI Firmware settings(BIOS)
In the side menu, go to keyboard
Turn on the lock fn and set it to run as traditional method.
That's it.

answered Jul 17 '24 at 07:37

Rishikesh

1

How can I toggle the Fn (function) key?

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