High Quality Content by WIKIPEDIA articles! AltGr (also Alt Graph, Alt Graphics, Alt Grill, Alt Car or Alt Char) 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.