Full-width ↔ Half-width Converter (全角 半角)
Convert full-width letters, digits and symbols (ＡＢＣ１２３) to normal half-width text and back, half-width katakana (ｶﾀｶﾅ) to full-width, plus spaces and Hangul.
Hiragana, kanji, Hangul syllables and the wave dash 〜 have no half-width form and are left as they are. Half-width ﾞ and ﾟ join the kana before them (ｶﾞ → ガ).
Japanese, Chinese and Korean text often mixes two widths of the same characters: full-width ＡＢＣ１２３ that take a whole square, and half-width ABC123. Forms, databases and search treat them as different characters, so 03－1234 and 03-1234 do not match. This converter turns full-width letters, digits, punctuation and spaces into ordinary ones (or the other way round), turns old half-width katakana such as ﾃﾞﾊﾟｰﾄ into ordinary デパート, and handles half-width Hangul letters and currency signs such as ￥ and ￦.
How to use this tool
- Paste the text.
- Choose “Standard” (half-width letters and digits, full-width katakana, which is what most systems expect), all half-width, or all full-width.
- Untick any group you want to leave alone, such as digits or spaces.
- Copy the converted text; the note lists what was changed.
Formula
Full-width ASCII = ASCII code point + 0xFEE0 (！ U+FF01 … ～ U+FF5E) · ideographic space U+3000 ↔ space U+0020
Half-width katakana (U+FF61–U+FF9F) map to their full-width forms by the Unicode compatibility tables. Their voiced marks are separate characters, so ｶ + ﾞ is joined into ガ and ﾊ + ﾟ into パ; going the other way, ガ is split into ｶﾞ. Half-width Hangul letters (U+FFA0–U+FFDC) map to the compatibility jamo ㄱ ㅏ, and the wide currency signs ￠ ￡ ￥ ￦ to ¢ £ ¥ ₩. Unicode NFKC normalization does much of the same, but it also changes other characters, such as ① into 1 and ㈱ into (株), which this tool leaves alone.
Example
With the standard setting, the first sample line Ｔｅｌ：０３－１２３４－５６７８ ﾃﾞﾊﾟｰﾄ ｶﾞｲﾄﾞ becomes Tel:03-1234-5678 デパート ガイド: 16 full-width letters, digits and symbols become ASCII, 2 ideographic spaces become normal spaces and 11 half-width kana characters (counting the voiced marks) become 7 full-width ones. On the second line ￥１，２８０ becomes ¥1,280.
Frequently asked questions
What is the difference between full-width (全角) and half-width (半角)?
Full-width characters fill the same square as a kanji or Hangul syllable; half-width ones take half of it. Computers encode them as different characters, so ＡＢＣ and ABC are not equal for searches, passwords or form checks.
Why convert half-width katakana to full-width?
Half-width katakana come from early terminals with limited space. Many modern systems reject or mangle them in email and forms, and Japanese style guides use full-width katakana, so “Standard” turns them into full-width while making letters and digits half-width.
Does it change Hangul syllables or kanji?
No. Hangul syllables, kanji and hiragana have only one width. Only the separate half-width Hangul letters in the U+FFA0 block are converted.
Last updated:
Page address with these inputs: https://kakao.mobile/tools/full-width-half-width-converter/
Cite or embed this tool
kakaoCalc. (2026, November 8). Full-width ↔ Half-width Converter (全角 半角). https://kakao.mobile/tools/full-width-half-width-converter/
“Full-width ↔ Half-width Converter (全角 半角).” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/full-width-half-width-converter/.
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