In System → PreferencesKeyboardLayoutOptionsAlt/Win key behavior in older Ubuntu versions or in GNOME Tweaks → Keyboard & MouseAdditional Layout OptionsAlt and Win behavior for Ubuntu 17.10 and later, there is a menu similar to the one in the following screenshot:

Keyboard Layout Options Dialog Box

What do Meta, Super, Hyper mean?

  • 3
    This dialogue doesn't exist in 13.10. Commented Jan 21, 2014 at 16:29
  • Is it possible to access this menu at all in more recent Ubuntu versions?
    – Entalpi
    Commented Jul 18, 2017 at 8:23
  • yes. I just opened the menu in Kubuntu 17.04
    – JPT
    Commented Aug 31, 2017 at 12:57
  • 2
    it's in GNOME Tweak in 18.04
    – cat
    Commented Aug 7, 2018 at 23:59

1 Answer 1


Meta, Super and Hyper are modifier keys that modify the key's function. They are specific to the Symbolics Space Cadet Keyboard used on Lisp machines back in the day. Their function is sometimes emulated using other keys.

Space Cadet Keyboard

  • Meta

    The Meta key is not found on modern keyboards. Its use is sometimes emulated with AltGr (on some international layouts) or the right Alt key on the others. In addition:

    • Sun keyboards have a meta key () as well
    • Emacs calls Esc the Meta key
  • Super

    The Super key is equivalent to the Windows logo key or the (command) key. In Ubuntu, it's just another name for the Windows logo key.

  • Hyper

    Hyper is the fourth (counting Ctrl) and last modifier on the Space cadet keyboard. In Ubuntu, its function is undefined (I think), but it can be mapped, as in the screen shot above, to the windows logo key, should it be needed.

Sun Microsystems Keyboard
Sun's keyboard had different modifiers.

Note that GNOME and X.org implement many modifiers. Meta, Super and Hyper are not Linux's way of dealing with any modifier keys, but merely three of them specific to the Space Cadet keyboard. There is also Menu, Compose, AltGr, Greek, Front, X and others.

However, by convention the Windows logo key is called Super, and it is not implemented as yet another modifier by X.org.

Furthermore, the definition of modifier keys depends on:

  • The keyboard itself

  • The keyboard layout

  • The driver

  • The operating system's implementation

It's therefore almost impossible to generalise this information. I've tried to be somewhat specific to Gnome/X.org using a Windows-style keyboard with one of the more popular layouts. To test your keyboard, you can run xev - its terminal output will tell you what modifiers have been detected for your keyboard.

Macintosh keyboard keys
The Macintosh keyboard has a completely different set of modifiers

Some additional information:

  • The Windows key is also sometimes called Meta. E.g. in KDE.

  • The Alt key is sometimes called Option, as this is its equivalent on Macintosh keyboards

  • The Compose key (not a modifier, but a dead key), also called Multi, is often mapped to the Menu key or the right Windows key.

  • The AltGr key I've mentioned is also called a third-level modifier. Each key on the keyboard has, potentially, four characters on it. The first level is the lowercase, then it goes uppercase, Alt + something, and Alt + Shift + something. For example, the four glyphs on my A key are a, A, æ and Æ.

It's all a mess :-)

As they've been addressed in the comments:

  • The Fn is not really comparable. It's a hardware key that's not directly interfaceable by the operating systems. Pressing Fn and another key causes an entirely different code to be sent to the operating system. Examples for this include XF86AudioMute, XF86Eject and so on. The Operating system can't detect whether fn is pressed or not.

  • The SysRq key is traditionally a label on the Print Screen key indicating its function if used with the modifier Alt. It is sometimes, especially on newer notebooks, mapped to Fn+Alt+Print. In Linux, it provides a few Magic shortcuts.

  • 6
    "Wikipedia claims the Windows key is sometimes called Meta, I didn't find any other reference for this." From Ubuntu11.04's help, it says: "What is the "meta" key? The the meta key is key between the Ctrl and Alt keys on your keyboard. It may sometimes be called the windows key, logo key, system key, or even the Ubuntu key. If you have an Apple keyboard, there will not be a meta key on your keyboard. The Command (Cmd) key can be used instead. The meta key serves a special function in Unity. If you press the meta key, the Dash is displayed. If you press and hold the meta key, the Launcher will
    – kercker
    Commented Apr 27, 2011 at 9:06
  • 6
    I have Ubuntu with both Unity and KDE, while Unity calls it Super (hold it down in 12.04 to see a quick command reference), KDE calls it Meta... >.<
    – marcus
    Commented May 8, 2012 at 14:17
  • 1
    It looks like nobody quite remembers what these keys were for. (: home.comcast.net/~mmcm/kbd/SpaceCadet.html Commented Apr 24, 2014 at 15:02
  • 2
    About the Meta key, it seems to me it's the left alt key. I don't see how AltGr could be used for anything else than entering other levels of characters. Commented Jul 29, 2015 at 0:48
  • 2
    As regards Meta, why do you mention right ALT and for international layouts ALTGR only? At least on US/UK keyboard the Meta can be both the left or right ALT. For international layouts the Meta can be the ALTGR replacing the right ALT, as you say, but also the left ALT.
    – antonio
    Commented Apr 23, 2017 at 16:28

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