Full-width / Half-width Converter (letters, digits, katakana)
Convert digits, letters, symbols, spaces, katakana and CJK punctuation between full-width and half-width, type by type, with exceptions and a preview of every change. Unlike NFKC, nothing else is rewritten.
- Runs in your browser (no upload)
Your original text is kept as is (up to 200,000 characters).
Characters entered here are never converted. Either width works and applies to both forms (e.g. （）＠).
Converted text
27 character(s) converted.
- Digits4
- Letters10
- Symbols3
- Katakana10
Preview of the changes
Ａbefore- A after
- （ exception
- ヶ cannot be converted
Unicode normalization (NFKC) is not used. NFKC would also rewrite ① → 1, ㈱ → (株) or ™ → TM, while this tool converts only the full-width and half-width forms of the types you choose. Characters that are not full-width forms, such as the wave dash 〜 or curly quotes “”, are not converted.
How to use
- Paste the text you want to convert.
- Pick a quick setting such as "Letters, digits, symbols half-width; katakana full-width", or choose half-width, full-width or keep for each type.
- Enter any characters that must stay unchanged, check the preview, then copy or save the result.
FAQ
How is this different from Unicode normalization (NFKC)?
NFKC also rewrites many compatibility characters, such as ① → 1, ㈱ → (株) and ™ → TM. This tool only uses a fixed full-width/half-width mapping table and converts only the types you select, so other characters stay as they are.
What happens to voiced half-width katakana?
Two half-width characters such as ｶﾞ become one full-width character ガ, and a full-width パ becomes the two half-width characters ﾊﾟ. A voiced mark that cannot be combined becomes the full-width mark ゛.
Why do ヶ and ヵ stay full-width?
Characters such as ヶ, ヵ, ヮ, ヰ and ヱ have no half-width form. Characters that could not be converted are listed with the result.
Notes & limitations
- What you enter is processed only on this page and is not sent to YUCTS servers.
- Characters without a full-width/half-width pair, such as the wave dash 〜, curly quotes “” and hiragana, are not converted.
- Hiragana cannot be made half-width (no half-width hiragana exists).
- Up to 200,000 characters can be converted.
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