AltGr (also Alt Graph, or Right Alt) is a modifier key found on some computer keyboards and is 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 macOS, the Option key has functions similar to the AltGr key.
AltGr is used similarly to the Shift key: it is held down when another key is struck in order to obtain a character other than the one that the latter normally produces. AltGr and Shift can also sometimes be combined to obtain yet another character. For example, on the US-International keyboard layout, the C key can be used to insert four different characters:
- C -> c (lower case -- first level)
- ? Shift+C -> C (upper case -- second level)
- AltGr+C -> © (copyright sign -- third level)
- AltGr+? Shift+C -> ¢ (cent sign -- fourth level)
Video AltGr key
Meaning
The meaning of the key's abbreviation is not explicitly given in many IBM PC compatible technical reference manuals. However, IBM states that AltGr is an abbreviation for alternate graphic, and Sun keyboards label the key as Alt Graph.
AltGr was originally introduced as a means to produce box-drawing characters, also known as pseudographics, in text user interfaces. 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.
Maps AltGr key
Control + Alt as a substitute
Originally, US PC keyboards (specifically, the US 101-key PC/AT keyboards) did not have an AltGr key because that was relevant to only non-US markets; they simply had "left" and "right" Alt keys.
The right Alt key is usually an equivalent of the AltGr key because both the right Alt key and the AltGr key share the same scancode and are indistinguishable by software. However, on some keyboards it may not be the case, i.e. the keyboard has two Alt keys, each of which acts as the left Alt key. On compact keyboards like those of netbooks, the right Alt key may be missing altogether. To allow the specific functionality of AltGr when typing non-English text on such keyboards, Windows allows 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, 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
In the US-International keyboard layout, the AltGr key can be used to enter the following characters:
¡ ² ³ ¤ EUR 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 many of these symbols can also be entered using dead keys; for example ä can be entered with " followed by a.
For comparison, the US-International keyboard layout follows. Note that the "`/~" key (left of number 1) has been omitted; it doesn't produce any characters together with the AltGr key with or without Shift.
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 and Ireland
In UK and Ireland keyboard layouts, the only two symbols printed on most keyboards which require the AltGr key are:
- EUR 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 matches the actual symbols that are printed on most UK keyboards; in Windows, the "UK keyboard layout" requires AltGr for the broken vertical bar and the vertical bar is a shifted key--the reverse 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. ¹²³EUR½{[]}@?e¶?<-?->øþæßð???j??«»¢""nµ??E®?¥??ØÞƧЪ??J&?<>©''Nº×÷·
Using the AltGr key on UK and 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 at QWERTY § United Kingdom (Extended) Layout.
South Slavic Latin
On South Slavic Latin keyboards (used in Croatia, Slovenia, Bosnia and Herzegovina, Montenegro and Serbia), the following letters and special characters are created using AltGr:
Belgian
On Belgian keyboards, AltGr enables the user to type the following characters (the first or only one shown is without ? Shift; when two characters are mentioned, the second one is with ? Shift). Those shown in bold are printed on the keys, and common to all systems; the others may be more variable, or specific to Unix-like systems. For travellers who want to use hotel PCs or cybercafés in Belgium, it is important to know that @ in email addresses is generated by a combination of AltGr + é (unshifted 2).
- Digits row
- AltGr+² -> ¬
- AltGr+1 -> | and ¡ (inverted exclamation mark, for Spanish)
- AltGr+2 -> @ and 1/8
- AltGr+3 -> #
- AltGr+4 -> ¼
- AltGr+5 -> ½ and 3/8
- AltGr+6 -> ^ and 5/8 -- the ^ is not dead here
- AltGr+7 -> { and 7/8 -- { is duplicate of AltGr+9, see below
- AltGr+8 -> [ and (TM) -- [ is duplicate of AltGr+^, see below
- AltGr+9 -> { and ±
- AltGr+0 -> }
- AltGr+) -> \ and ¿ -- \ is duplicate of AltGr+<, see below
- AltGr+- -> dead cedilla and dead ogonek, as in ç and ?
- Top letters row
- AltGr+A -> @ and ? -- @ is duplicate of AltGr+2, see above
- AltGr+Z -> ? and ? -- both duplicates of AltGr+L, see below
- AltGr+E -> EUR and ¢ -- for ¢ see also AltGr+C below
- AltGr+R -> ¶ and ®
- AltGr+T -> ? and ?
- AltGr+Y -> <- and ¥
- AltGr+U -> ? and ?
- AltGr+I -> -> and ? (right arrow and Turkish dotless i)
- AltGr+O -> oe and OE
- AltGr+P -> þ and Þ (Icelandic thorn)
- AltGr+^ -> [ and dead ball, as in å
- AltGr+$ -> ] and dead macron, as in ?
- Middle letters row (Home row)
- AltGr+Q -> æ and Æ
- AltGr+S -> ß (German eszett aka sharp s)
- AltGr+D -> ð and Ð (Icelandic edh)
- AltGr+F -> ? and ª ("feminine" exponent-a for Spanish etc.)
- AltGr+G -> ? and ?
- AltGr+H -> ? and ?
- AltGr+K -> ?
- AltGr+L -> ? and ? -- see also AltGr+Z, above
- AltGr+M -> dead acute and dead double-acute, as in ó and ?
- AltGr+ù -> dead acute and dead caron, as in ? and ?
- AltGr+µ -> dead grave and dead breve, as in ì and ?
- Note: Depending on the hardware, the latter key may also be two rows higher, with <- Backspace narrower and ? Enter wider to compensate.
- Bottom letters row
- AltGr+< -> \
- AltGr+W -> «
- AltGr+X -> »
- AltGr+C -> ¢ and © -- for ¢ see also AltGr+? Shift+E above
- AltGr+V -> " and ' -- "shape 6 above" quotation marks (opening in English, closing in German)
- AltGr+B -> " and ' -- "shape 9 above" quotation marks (closing in English)
- AltGr+, -> dead cedilla, as in Ç
- AltGr+; -> (nothing) and × (multiplication sign)
- AltGr+: -> · and ÷ (middle dot as in Catalan col·lega "colleague", and division sign)
- AltGr+= -> dead tilde and dead dot above, as in ñ and ?
Brazilian
' 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 the AltGr key:
¹ ² ³ £ ¢ ¬ § / ? ° ª º ? °
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 software (e.g. Microsoft Word) will map AltGr+R to ® and AltGr+T to (TM), but this is not standard behavior and was likely an accident owing to the fact that the combinations Ctrl+Alt+R and Ctrl+Alt+T were intended. Windows interprets Ctrl+Alt as 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).
French
On AZERTY keyboards, AltGr enables the user to type the following characters:
German
On German keyboards, AltGr enables the user to type the following characters, which are indicated on the keyboard:
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:
There is an alternate layout, which differ just in disposition of characters accessible through AltGr and includes the tilde and the curly brackets.
Latvian
Having Latvian set as the system language, the following letters can be input using AltGr.
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), Faroe Islands (FO), 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 Latin base letter has been reserved for another combination:
- AltGr+A -> ?
- AltGr+C -> ?
- AltGr+E -> ?
- AltGr+L -> ?
- AltGr+N -> ?
- AltGr+O -> ó
- AltGr+S -> ?
- AltGr+X -> ?
- AltGr+Z -> ?
At the time of the political transformation and opening of commercial import channels this practice was so widespread that it was adopted as the de facto 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. On current versions it is referred to as Polish (214).
Romanian
The keymap with the AltGr key:
â ß EUR r ? y u î o § ,, " ? ? ? f g h j k ? ; z x © v b n m « »
Turkish
In Turkish keyboard variants the AltGr can be used to display the following characters:
Dutch (The Netherlands)
- Digits row
- AltGr+1 -> ¹ and ¡
- AltGr+2 -> ²
- AltGr+3 -> ³
- AltGr+4 -> £ and ¤
- AltGr+5 -> EUR
- AltGr+6 -> ¼
- AltGr+7 -> ½
- AltGr+8 -> ¾
- AltGr+9 -> '
- AltGr+0 -> '
- AltGr+- -> ¥
- AltGr+= -> × and ÷
- Top letters row
- AltGr+Q -> ä and Ä
- AltGr+W -> å and Å
- AltGr+E -> é and É
- AltGr+R -> ®
- AltGr+T -> þ and Þ (Icelandic thorn)
- AltGr+Y -> ü and Ü
- AltGr+U -> ú and Ú
- AltGr+I -> í and Í
- AltGr+O -> ó and Ó
- AltGr+P -> ö and Ó
- AltGr+[ -> «
- AltGr+] -> »
- AltGr+\ -> ¬ and ¦
- Middle letters row (Home row)
- AltGr+A -> á and Á
- AltGr+S -> ß (German eszett aka sharp s) and §
- AltGr+D -> ð and Ð (Icelandic edh)
- AltGr+L -> ø and Ø
- AltGr+; -> ¶ and °
- AltGr+' -> ´ and ¨
- Bottom letters row
- AltGr+Z -> æ and Æ
- AltGr+C -> © and ¢
- AltGr+N -> ñ and Ñ
- AltGr+M -> µ
- AltGr+, -> ç and Ç
- AltGr+/ -> ¿
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 -> ?
- 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.
Swedish key map
In this diagram over the Swedish X Window key map, the grey symbols are the standard characters, yellow is with shift, red is with AltGr, and blue is with Shift+AltGr.
Danish keymap
½ 1 2 3 4 5 6 7 8 9 0 + ´ 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 AltGr key:
@ £ $ { [ ] } | EUR ~ \ µ
See also
- Modifier key
- Option key
- Shift key
- Dead key
- Compose key
- Windows Alt keycodes
- Precomposed character
References
Source of the article : Wikipedia
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