Japanese Input Method

By Xah Lee. Date: . Last updated: .

Here is a introduction to Japanese Input Method.

mac japan input 2019-12-21 rfjrq
MacOS Japanese Input preference 2019-12-21

Japanese Writing System

How to Type Japanese

Writing Japanese is hard. You need:

There are 2 major systems to input hiragana:

To input kanji, press a “conversion” key , then it'll convert previous kana character or phrase to kanji. Because there are many homonyms, typically a selection will popup to let you pick the correct kanji.

To input katakana, either switch to a dedicated katakana mode, or, the katakana shows as a choice among kanji character choices.

To input English letters (romaji), switch to romaji mode that lets you enter the English letters as is.

Japanese input method menu 39864
Progression of typing Japanese. First type English letters, it becomes hiragana, then press “conversion” a key, then choices of kanji or katakana.

That's the basics.

Most people in Japan, use romaji method to input Japanese. That is, on a normal PC keyboard with QWERTY layout, type the English letters of the kana reading, and it becomes the hiragana character, and press a key to convert the previous word to kanji or katakana (if desired).

This is a inefficient method, but requires no learning.

Special Keys on Japanese Keyboards

Japanese keyboard layout
Japanese keyboard layout. image source

Keyboards sold in Japan usually have special keys.

They are not necessary, as you can type Japanese with US keyboard. When a keyboard doesn't have these special keys, usually Space, Return, or a Ctrl combination works.

Here are the special keys.

Reads “henkan”, meaning “conversion”. Convert to kanji. Sometimes the key is labeled by circular arrows 🗘. If the key doesn't exist, usually Space does the same.
Reads “muhenkan”, meaning “no conversion”. If the key doesn't exist, usually Return does the same.
かな or kana
Kana mode.
Hiragana mode. Or Ctrl+CapsLock
Katakana mode.
Rōmaji mode.
Alphanumeric mode. (if not exist, usually CapsLock does the same. For actual caps lock, press Shift+CapsLock)
Half-width/Full-width. Toggles the system to use full-width or half-width characters for English letters and punctuations.

What is Full-Width, Half-Width

Each character in Japanese and Chinese is a square. Text is aligned vertically, forming a grid. But when English or western text is mixed in, that breaks the alignment, because the size of English alphabets are not squares.

So, there's the idea of Full-Width Characters for English alphabet, digits, and punctuations, where each character has the same width as the square, so that the text has columns aligned.

Note: these are special characters, not font.

So, in Chinese or Japanese input, there's usually a key 半角/全角 or software toggle for user to chose between full-width or half-width for English characters. Half-with means using the normal English characters (may be in proportional font or monospace font).

half width. (use proportional font for English alphabet, digits, punctuations.)

Sometimes shown as a crescent moon icon 🌙 or or

Full width. (use proportional font for English alphabet, digits, punctuations.) monospace font. Sometimes shown as a white full moon circle 🌕.

Note: Full-width English letters in Japanese text is not necessarily preferred, since English in full-width doesn't look good.

Japanese Keyboard Layouts

International Layouts

Western Europe Layouts

Chinese and Japanese