Half-width Kana

Half-width kana (半角カナ, Hankaku kana?) are katakana characters displayed at half their normal width (a 2:1 aspect ratio), instead of the usual square (1:1) aspect ratio. For example, the usual (full-width) form of the katakana ka is カ while the half-width form is ｶ. There are no half-width hiragana or kanji.

Half-width kana were used in the early days of Japanese computing, to allow Japanese characters to be displayed on the same grid as monospaced fonts of Latin characters. Half-width hiragana or kanji were not used. Half-width kana characters are not generally used today, but find some use in specific settings, such as cash register displays, on shop receipts, and Japanese digital television and DVD subtitles. They also find occasional use online (in email or webpages) – for example, anata (あなた?, you) (normally written in hiragana or sometimes kanji 貴方) might be written as ｱﾅﾀ.

The term "half-width kana", which strictly refers only to how kana are displayed, not how they are stored – is also used loosely to refer to the A0–DF (hexadecimal) block where katakana are stored in some character encodings, such as JIS X 0201 (1969) – see encodings, below. This is formally incorrect, however – this JIS standard simply specifies that katakana be stored in these locations, without specifying how they should be displayed; the confusion is because in early computing, the characters stored here were in fact displayed as half-width kana – see confusion, below.