On Windows, the key combination Alt + 2+ 5+ 5 creates a blank space. How can I achieve this on Ubuntu?

  • As this is a lot more cumbersome under Linux than on Windows: Is there a table?
    – empedokles
    Commented Apr 23, 2015 at 10:21
  • 3
    @empedokles I always use unicode-table.com, but the Character Map application also shows the unicode value of the selected character in the status bar.
    – mjumbewu
    Commented Sep 18, 2016 at 12:22

2 Answers 2


When you type Alt + numbers in Windows, you are actually typing Alt + character's ASCII code.

To achieve the same in Ubuntu, you must type Ctrl + Shift + U, and then type Unicode codepoint.

If this shurtcut doesn't work check if your input method is iBus.

Example 1

  • Alt + 255 on Windows creates a non-breaking space (ASCII 255)
  • This character in Unicode is U+00A0
  • On Ubuntu, type it as Ctrl + Shift + U then A, then 0, then Space or Enter or just release all keys

Example 2

  • Alt + 173 on Windows creates an inverted exclamation mark (ASCII 173, "¡")
  • This character in Unicode is U+00A1
  • On Ubuntu, type it as Ctrl + Shift + U then A, then 1, then Space or Enter or just release all keys.

The Unicode four-digit hexadecimal number can be found via the Character Map (gucharmap). For just ASCII table type man ascii on a terminal.


  • 1
    I also would like to know the unicode code for windows alt+173 in ubuntu.
    – Valladao
    Commented Dec 17, 2011 at 5:33
  • 14
    You don't need to hold Ctrl-Shift for the whole number, you can release them after the "u", and add a space at end of code.
    – enzotib
    Commented Dec 17, 2011 at 6:58
  • @Valladao, I updated my answer to better explain how to type these characters in general, and I included both 173 and 255 as examples. Commented Dec 17, 2011 at 15:13
  • @enzotib nice to know I can let go of those keys and actually type with my left hand. :) Commented Dec 17, 2011 at 15:13
  • it may be important to note, that this won't work if your caps are locked Commented Aug 11, 2014 at 0:10

Another way — «Compose key»

A compose key, available on some computer keyboards, is a special kind of modifier key designated to signal the software to interpret the following (usually two) keystrokes as a combination in order to produce a character not found directly on the keyboard. For example, striking Compose followed by O and then C can produce the symbol ©, the copyright symbol). wikipedia.org

  • ENABLE [Ubuntu 13.04]: System settings... → Keyboard → Layout settings → Options → «Compose key position» and set it, for example, on «Menu» (key between right ALT and CTRL).

  • DO: Hold key «Menu» and push «Space» 2 times. Should get 1 non-breaking space: « ».

Here more Linux compose key sequences: hermit.org

  • 2
    FWIW, in 14.04 the compose setting is under System settings -> keyboard -> shortcuts -> typing -> compose key Commented Feb 16, 2015 at 3:12
  • Compose key is neat! I now found a good replacement for the CapsLock key and am able to easily insert the various symbols that I used to struggle with earlier.
    – eshwar
    Commented Nov 23, 2015 at 6:46
  • Sadly you can't bind compose cay anyway (Win key), but place it on Caps lock is maybe even better! I hate accidentally caps lock key pressing :)
    – iiic
    Commented Jul 3, 2017 at 13:23
  • See answer for Ubuntu 18.04 and later: askubuntu.com/a/1028964/493153 Commented May 26, 2019 at 8:58

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