Convert between full-width and half-width, choosing letters, symbols, katakana, and spaces
Full-width to Half-width turns characters like ＡＢＣ１２３ into ABC123; the reverse does the opposite. Only the ticked targets are converted; everything else is left unchanged.
Letters/digits covers A-Z/a-z/0-9, symbols covers ASCII punctuation such as ! ? # ( ), katakana converts between half-width and full-width katakana (including composing/decomposing dakuten and handakuten), and spaces converts between a regular space and the ideographic space (U+3000).
Normalize inconsistent form input (mixed full-width and half-width digits in names, addresses, phone numbers), fix half-width katakana into full-width for clean data, or standardize symbols to half-width before pasting into CSV or code.
Yes. Half-width characters like ｶﾞ or ﾊﾟ are correctly composed into full-width ガ or パ. In the reverse direction, dakuten and handakuten are decomposed.
No. All conversion runs in your browser (JavaScript); your input is never sent to a server.
No. Hiragana has no half-width form, so it is out of scope. This tool handles only full/half-width letters, ASCII symbols, katakana, and spaces.