Full-width ⇔ Half-width Converter
＋More features: convert only selected character types, and check for stray full-width characters
Choose which character types to convert
Lets you convert only what you need, for example “digits only”. Selecting katakana also enables conversion to and from half-width katakana (ｱｲｳ).
Check for stray full-width or half-width katakana characters
Inspects the “Text” box above and lists where any full-width letters, digits, symbols and spaces, or half-width katakana, are hiding.
Full-width (zenkaku) characters are the wide versions of letters, digits and symbols that Japanese input methods produce — ＡＢＣ１２３ instead of ABC123 — and although they look similar, a computer treats them as completely different characters from the ordinary half-width (hankaku) ones. Paste your text here and this tool converts full-width letters, digits, symbols and spaces to half-width (the reverse direction works too). Hiragana, katakana and kanji are left untouched. Use it for Japanese application forms that say “please enter in half-width”, or to make an address book or name list consistent.
How to use
- Choose the direction (full-width → half-width, or half-width → full-width).
- Paste your text and the converted result appears instantly. No button needed.
- Use the “Copy” button on the result and paste it back where you need it.
How it works
- Full-width letters, digits and symbols (Ａ–／, ！–～) correspond to their half-width forms in a regular way in Unicode (a difference of 0xFEE0). The conversion follows that correspondence, character by character.
- The full-width space (U+3000) and the half-width space (U+0020) are converted too.
- Hiragana, katakana and kanji are left as they are (no conversion to so-called half-width katakana in the main form).
Sources and assumptions
- A purely mechanical conversion based on the Unicode correspondence between full-width and half-width forms (Halfwidth and Fullwidth Forms).
Assumptions and notes
- The main form does not convert half-width katakana (ｱｲｳ) into full-width katakana.
- Some fields, such as addresses and names, are required to be in full-width by the organisation you are submitting to. Follow the instructions on the form.
Frequently asked questions
Why do Japanese forms tell me to “enter in half-width”?
So that the system can process the value internally as a number or as Latin letters. Full-width “１２３” looks similar but consists of different characters, so it may not be treated as a number as it stands.
Can I turn katakana into half-width (ｶﾀｶﾅ) too?
The main form does not do this. Half-width katakana is a common cause of garbled text, so it is generally avoided nowadays (except in special cases such as some banking forms). Tick “Katakana” under “＋More features” if you do need it.
Is the text I paste sent anywhere?
No. All conversion happens inside your own device.