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The AltGr key typically takes the place of the right-hand Alt key.

A keyboard with additional engravings showing third-level and fourth-level characters included in the US-International keyboard layout.

AltGr (also Alt Graph, Alt Graphics, Alt Grill, Alt Car or Alt Char) (pronounced "alt gear") is a modifier key found on many computer keyboards and primarily used to type characters that are unusual for the locale of the keyboard layout, such as currency symbols and accented letters. On a typical IBM compatible PC keyboard, the AltGr key, when present, takes the place of the right-hand Alt key. In Mac OS X, the Option key has functions similar to the AltGr key.

AltGr is effectively comparable with the Shift key, which can be used in combination with a character-printing key to type a second-level character – typically the uppercase variant of a letter. With the help of the AltGr key, the same printing key can be used to produce a third-level character (which may be visible, sometimes in a different color, on the front vertical face or the bottom right of the key top). Using AltGr and Shift together often provides access to even a fourth-level character. For example, on the US-International keyboard layout, the C key can be used to insert four different characters:

• C → c (lowercase)
• ⇧ Shift+C → C (uppercase)
• AltGr+C → © (copyright sign)
• AltGr+⇧ Shift+C → ¢ (cent sign)

Meaning

Sun Microsystems keyboard, which labels the key as Alt Graph.

The meaning of the key's abbreviation is not explicitly given in many IBM PC compatible technical reference manuals.^{[citation needed]} However, IBM states that AltGr is an abbreviation for alternate graphic,^[1][2] and Sun keyboards label the key as Alt Graph.

Apparently, AltGr was originally introduced as a means to produce box-drawing characters, also known as pseudographics, in text user interfaces.^[3] These characters are, however, much less useful in graphical user interfaces, and rather than alternate graphic the key is today used to produce alternate graphemes.

Control + Alt as a substitute

Originally, US PC keyboards (specifically, the US 101-key PC/AT keyboards) did not have an AltGr key, it being relevant to only non-US markets; they simply had "left" and "right" Alt keys.

As those using such US keyboards increasingly needed the specific functionality of AltGr when typing non-English text, Windows began to allow it to be emulated by pressing the Alt key together with the Control key:

Ctrl+Alt ≈ AltGr

Therefore, it is recommended that this combination not be used as a modifier in Windows keyboard shortcuts as, depending on the keyboard layout and configuration, someone trying to type a special character with it may accidentally trigger the shortcut,^[4] or the keypresses for the shortcut may be inadvertently interpreted as the user trying to input a special character.

Function

International keyboard layouts

US international

On US international keyboard layouts, the AltGr key can be used to enter the following characters:

¡ ² ³ ¤ € ¼ ½ ¾ ‘ ’ ¥ ×
 ä å é ® þ ü ú í ó ö « »
  á ß ð           ø ¶ ´ ¬
   æ   ©     ñ µ ç   ¿

And, in combination with the Shift key:

¹     £               ÷
 Ä Å É   Þ Ü Ú Í Ó Ö
  Á § Ð           Ø ° ¨ ¦
   Æ   ¢     Ñ   Ç

Note that a lot of these symbols can also be entered using dead keys.

For comparison, the US international keyboard layout follows. Note that the "`/~" key has been omitted; it does not react to the AltGr key.

1 2 3 4 5 6 7 8 9 0 - =
 Q W E R T Y U I O P [ ]
  A S D F G H J K L ; ' \
 m Z X C V B N M , . /

Here "m" denotes the "Macro" key. It generally produces a "\", although applications receive a different keycode and can therefore instead use the key to, for example, run macros.

UK & Ireland

In UK & Ireland keyboard layouts, the only two symbols printed on most keyboards which require the AltGr key are:

• € the Euro currency symbol. Located on the "4/$" key.
• Either |, the vertical bar ("pipe symbol") or ¦, the broken vertical bar ("broken pipe symbol"). Located on the "`/¬" key, to the immediate left of "1". The other bar symbol is the shift-keyed symbol on the "\" key immediately to the left of the Z key.

The two latter symbols interchange places in UK keyboards according to the operating system in use. In OS/2, the "UK keyboard layout" (specifically: the UK166 layout) requires AltGr for the vertical bar and the broken vertical bar is a shifted key—which, coincidentally, matches the actual symbols that are printed on most^{[citation needed]} UK keyboards; in Windows, the "UK keyboard layout" requires AltGr for the broken vertical bar and the vertical bar is a shifted key—the converse of what is usually printed on the keys; and in Linux, the "UK keyboard layout" produces the unbroken vertical bar with both AltGr plus "`/¬" and shifted \, and produces the broken vertical bar with AltGr plus shifted \.

Using the AltGr key on Linux produces many foreign characters and international symbols, e.g. ¹²³€½¾{[]}@łe¶ŧ←↓→øþæßðđŋħjĸł«»¢“”nµΩŁE®Ŧ¥↑ıØÞƧЪŊĦJ&Ł<>©‘’Nº×÷·

Using the AltGr key on UK & Irish keyboards in some versions of Windows (for example XP) in combination with vowel characters produces acute accents also known as "fadas" in the Irish language over the vowels (for example, á,é,í,ó,ú and Á,É,Í,Ó,Ú).

The UK-Extended keyboard available in versions of Microsoft Windows from XP with SP2, and Linux allows many characters with diacritical marks, including accents, to be generated by using the AltGr key in combination with others. Details are to be found in the article on QWERTY.

Croatian, Slovene, Bosnian and Serbian (Latin)

On Croatian, Slovene, Bosnian and Serbian (Latin) keyboards, the following letters and special characters are created using AltGr:

Finnish multilingual

The Finnish multilingual keyboard standard adds many new characters to the traditional layout via the AltGr key, as shown in the image below (the blue characters can be written with the AltGr key; several dead key diacritics, shown in red, are also available as an AltGr combination).^[5][6]

French

On French keyboards, AltGr enables the user to type the following characters:

German

On German keyboards, AltGr enables the user to type the following characters:

Hebrew

On Hebrew keyboards, AltGr enables the user to type the following characters:

Yiddish

Utilizing a Hebrew keyboard, one may write in Yiddish as the two languages share many letters. However, Yiddish has some additional digraphs and a symbol not otherwise found in Hebrew which are entered via AltGr.

Italian

On Italian keyboards, AltGr enables the user to type the following characters:

Latvian

Having Latvian set as the system language, the following letters can be input using Alt Gr.

Macedonian

On Macedonian keyboards, AltGr enables the user to type the following characters:

Nordic and Estonian

The keyboard layouts in the Nordic countries Denmark (DK), Finland (FI), Norway (NO) and Sweden (SE) as well as in Estonia (EE) are largely similar to each other. Generally the AltGr key can be used to create the following characters:

Other AltGr combinations are peculiar to just some of the countries:

Polish

Typewriters in Poland used a QWERTZ layout specifically designed for the Polish language with accented characters obtainable directly. When personal computers became available worldwide in the 1980s commercial importing into Poland was not supported by its communist government, so most machines in Poland were brought in by private individuals. Most had US keyboards, and various methods were devised to make special Polish characters available. An established method was to use AltGr in combination with the relevant Latin base letter to obtain a precomposed character with a diacritic; note the exceptional combination using x instead of the base letter z, as the letter has been reserved for another combination:

• AltGr+A → ą
• AltGr+C → ć
• AltGr+E → ę
• AltGr+L → ł
• AltGr+N → ń
• AltGr+O → ó
• AltGr+S → ś
• AltGr+X → ź
• AltGr+Z → ż

At the time of the political transformation and opening of commercial import channels this practice was so widespread that it was adopted as the standard. Nowadays most PCs in Poland have standard US keyboards and use the AltGr method to enter Polish diacritics. This layout is referred to as Polish programmers' layout (klawiatura polska programisty) or simply Polish layout.

Another layout is still used on typewriters, mostly by professional typists. Computer keyboards with this layout are available, though difficult to find, and supported by a number of operating systems; they are known as Polish typists' layout (klawiatura polska maszynistki). Older Polish versions of Microsoft Windows used this layout, describing it as Polish layout.

Turkish

In Turkish keyboard variants the AltGr can be used to display the following characters:

• AltGr+E → €
• AltGr+q → @
• AltGr+ü a → ã
• AltGr+ğ a → ä

X Window System

In the X Window System (GNU/Linux, BSD, Unix), AltGr can often be used to produce additional characters with almost every key on the keyboard. For example, the Danish keymap features the following key combinations:

• AltGr+⇧ Shift+Q → Ω
• AltGr+O → ø
• AltGr+M → µ

The Italian keymap includes, among other combinations, the following:

With some keys, AltGr produces a dead key; for example on a UK keyboard, semicolon can be used to add an acute accent to a base letter, and left square bracket can be used to add a trema:

• AltGr+; followed by E → é
• AltGr+[ followed by ⇧ Shift+O → Ö

This use of dead keys enables one to type a wide variety of precomposed characters that combine various diacritics with either uppercase or lowercase letters, achieving a similar effect to the Compose key.

Modified key tables

Swedish keymap

In this diagram, the grey symbols are the standard characters, yellow is with shift, red is with AltGr, and blue is with Shift+AltGr.

Danish keymap

 q  w  e  r  t  y  u  i  o  p  å  ¨
  a  s  d  f  g  h  j  k  l  æ  ø  '
<  z  x  c  v  b  n  m  ,  .  -

The keymap with the Alt Gr key:

 @  ł  €  ®  þ  ←  ↓  →  œ  þ  "  ~
  ª  ß  ð  đ  ŋ  ħ  j  ĸ  ł  '  ^  ˝
\  «  »  ©  “  ”  n  µ  ¸  ·

The keymap with Alt Gr+Shift:

 Ω  Ł  ¢  ®  Þ  ¥  ↑  ı  Œ  Þ  ˚  ˇ
  º  §  Ð  ª  Ŋ  Ħ  J  &  Ł  ˝  ˇ  ×
¬  <  >  ©  `  '  N  º  ˛  ˙  ˙

Brazilian ABNT2 keymap

'  1  2  3  4  5  6  7  8  9  0  -  =
 q  w  e  r  t  y  u  i  o  p  ´  [
  a  s  d  f  g  h  j  k  l  ç  ~  ]
\  z  x  c  v  b  n  m  ,  .  ;  /

The keymap with Shift:

"  !  @  #  $  %  ¨  &  *  (  )  _  +
 Q  W  E  R  T  Y  U  I  O  P  `  {
  A  S  D  F  G  H  J  K  L  Ç  ^  }
|  Z  X  C  V  B  N  M  <  >  :  ?

The keymap with the AltGr key:

   ¹  ²  ³  £  ¢  ¬                 §
 /  ?  °                          ª
                                   º
         ₢                       °

The AltGr+Shift combination does not result in any character by default in Windows.

Some notes:

• The AltGr+C combination results in the (obsolete) symbol for the former Brazilian currency, the Brazilian cruzeiro.
• The AltGr+Q, AltGr+W, AltGr+E combinations are useful as a replacement for the "/?" key, which is physically absent on non-Brazilian keyboards.
• Some softwares (e.g. Microsoft Word) will map AltGr+R to ® and AltGr+T to ™, but this is not standard behavior.

Romanian keymap

The keymap with the AltGr key:

 â  ß  €  r  ț  y  u  î  o  § „ ”
  ă  ș  đ  f  g  h  j  k  ł  ;
    z x © v b n m « »

See also

• Modifier key
• Option key
• Shift key
• Dead key
• Compose key
• Windows Alt keycodes
• Precomposed character

References