Full-width ⇄ Half-width Converter
Convert only what you want: tick alphanumerics, symbols, katakana or spaces independently and choose a direction. Voiced and semi-voiced half-width kana (ｶﾞ ↔ ガ, ﾊﾟ ↔ パ) are handled as single characters.
Categories
Alphanumerics (０-９Ａ-Ｚａ-ｚ ⇄ 0-9A-Za-z), ASCII symbols and their full-width forms, katakana (ｱ ⇄ ア including voiced marks, the long vowel mark, punctuation and brackets), and the ideographic space U+3000 ⇄ ASCII space. Hiragana has no half-width form and is left alone.
Why voiced kana matter
Half-width ガ is two characters, ｶ plus ﾞ. A naive one-to-one mapping produces カ゛. This tool matches the pair first and emits the single precomposed ガ, and decomposes it again in the other direction.
Typical uses
Normalising names and addresses, cleaning form input, producing half-width kana for a legacy system, or converting only digits while leaving full-width punctuation in place. For heavier normalisation, consider NFKC.
Frequently asked questions
Can hiragana be made half-width?
No — Unicode has no half-width hiragana. Convert to katakana first.
Can I convert digits but keep symbols full-width?
Yes. Tick "alphanumerics" and untick "symbols"; the four categories are independent.
How many characters is a half-width ガ?
Two (ｶ and ﾞ), which matters when a system imposes a character limit.
How is this different from NFKC?
NFKC also rewrites circled numbers (① → 1) and ligatures (㍿ → 株式会社). Use this tool when you want to change only specific categories.