The 半角 katakana block also holds ｡ ｢ ｣ ､ ･ ｰ, so these follow the katakana setting. Nothing you type leaves your browser.
About the fullwidth halfwidth converter
Japanese computers have two widths of characters. Fullwidth (全角, zenkaku) characters are as wide as a kanji: ＡＢＣ１２３. Halfwidth (半角, hankaku) characters are narrow: ABC123, and there is even narrow katakana: ｶﾀｶﾅ.
Forms in Japan are strict about this. A bank form wants the name in 全角 katakana, an online shop wants the phone number in 半角 digits, and an old system only takes 半角 カナ. This tool does the 全角半角変換 for you. You choose for each kind of character — letters, digits, symbols, spaces and katakana — and it also turns hiragana into katakana and back.
Features
- Each kind on its own — letters, digits, symbols, spaces and katakana each get Keep, 全角 or 半角
- Voiced marks done right — ｶﾞ becomes ガ and ﾊﾟ becomes パ (one character), and back again
- Hiragana ⇄ katakana — ひらがな to カタカナ and back, in the same step
- Quick settings — all 全角, all 半角, or the common office style 英数 半角 + カナ 全角
- Changes are marked — you see at once which characters were changed, and how many
- Exact round trip — all printable ASCII and every katakana with a halfwidth form convert there and back without loss
- Private — the text never leaves your browser
What changes
| Kind | Halfwidth 半角 | Fullwidth 全角 |
|---|---|---|
| Letters | ABC abc | ＡＢＣ ａｂｃ |
| Digits | 0123456789 | ０１２３４５６７８９ |
| Symbols | ! ? # ( ) @ ~ | ！ ？ ＃ （ ） ＠ ～ |
| Space | one narrow space | one wide space (U+3000) |
| Katakana | ｶﾀｶﾅ ﾃﾞｰﾀ | カタカナ データ |
| Kana punctuation | ｡ ｢ ｣ ､ ･ ｰ | 。 「 」 、 ・ ー |
| Money signs | ¥ ¢ £ ₩ | ￥ ￠ ￡ ￦ |
Kanji and hiragana have only one width, so they never change size. Hiragana changes only when you choose To katakana.
Halfwidth katakana and the voiced marks
In 半角 katakana the two dots (゛ dakuten) and the circle (゜ handakuten) are separate characters. So ｶﾞ is two characters, but ガ is one. The tool joins and splits them for you:
| 半角 | 全角 |
|---|---|
| ｶﾞ ｷﾞ ｸﾞ ｹﾞ ｺﾞ | ガ ギ グ ゲ ゴ |
| ｻﾞ ｼﾞ ｽﾞ ｾﾞ ｿﾞ | ザ ジ ズ ゼ ゾ |
| ﾀﾞ ﾁﾞ ﾂﾞ ﾃﾞ ﾄﾞ | ダ ヂ ヅ デ ド |
| ﾊﾞ ﾋﾞ ﾌﾞ ﾍﾞ ﾎﾞ | バ ビ ブ ベ ボ |
| ﾊﾟ ﾋﾟ ﾌﾟ ﾍﾟ ﾎﾟ | パ ピ プ ペ ポ |
| ｳﾞ ﾜﾞ ｦﾞ | ヴ ヷ ヺ |
A few katakana have no halfwidth form: ヮ ヵ ヶ ヰ ヱ. They stay fullwidth.
What Japanese forms ask for
| The form says | Settings in the tool |
|---|---|
| 半角英数字で入力 (letters and digits in halfwidth) | Letters and Digits → Halfwidth 半角 |
| 数字は半角で (digits in halfwidth) | Digits → Halfwidth 半角 |
| 全角カタカナで入力 (fullwidth katakana) | Katakana width → Fullwidth, Hiragana / katakana → To katakana |
| 半角カナで入力 (halfwidth katakana) | Katakana width → Halfwidth, Hiragana / katakana → To katakana |
| ひらがなで入力 (hiragana) | Hiragana / katakana → To hiragana |
| 全角で入力 (everything fullwidth) | Quick setting All to 全角 |
For example, ﾔﾏﾀﾞ ﾀﾛｳ with the office setting becomes ヤマダ タロウ, and ＡＢＣ１２３ becomes ABC123.
Frequently asked questions
What is the difference between 全角 and 半角?
全角 (zenkaku) characters take a full square, the width of one kanji. 半角 (hankaku) characters take half of it. Old Japanese computers had a small halfwidth set (ASCII and katakana) and a large fullwidth set, and many forms still check which one you used.
Why does a form reject my text when it looks right?
Ａ and A, or ｱ and ア, look alike but are different characters for a computer. If the form wants 半角 digits, "１２３" is wrong even though it looks like 123. Convert it here and paste it again.
Why did 。 and 「」 change?
The 半角 katakana block also has ｡ ｢ ｣ ､ ･ and ｰ. They follow the Katakana width setting, so a text in 半角 カナ gets its punctuation in 半角 too. Choose Keep for katakana if you only want to change letters and digits.
Does it change kanji?
No. Kanji, hiragana and Korean or Chinese characters have only one width. Only hiragana ⇄ katakana changes the kana themselves.
What happens to ー when I change katakana to hiragana?
The long mark ー stays as it is: コーヒー becomes こーひー. Japanese writes it the same way in both scripts.
Is my text sent anywhere?
No. The conversion runs in your browser and nothing is saved.
Related tools
- Furigana Converter — readings for kanji, all hiragana or romaji
- Japanese Keyboard — type hiragana and katakana online
- Japanese Era Converter — 和暦 ⇄ 西暦 for forms
- Case Converter — UPPERCASE, lowercase and Title Case
- Character Counter — count the characters of a text
- Korean English Typing Converter — fix Korean typed on the wrong keyboard
How to use it
- Paste your text in the left box. The converted text shows on the right at once
- Pick a quick setting, or choose Keep, 全角 or 半角 for each kind of character
- Use Hiragana / katakana to turn ひらがな into カタカナ or back
- Changed characters are marked, and the line under the boxes says how many
- Press Copy and paste the text into your form
