Full-width and half-width converter
Paste Japanese or mixed text and convert letters, digits, symbols, spaces and katakana between full-width and half-width forms, or switch between hiragana and katakana.
Half-width katakana with voicing marks (ｶﾞ, ﾊﾟ) become one full-width character, and full-width ones split into two half-width characters. Kanji and hiragana stay as they are.
How to use it
- Pick a conversion: "Full-width → half-width", "Half-width → full-width", "Hiragana → katakana" or "Katakana → hiragana".
- For a width conversion, choose what to change under "Characters to convert": "Letters", "Digits", "Symbols", "Spaces" and "Katakana". Untick any kind you want to leave as it is.
- Type or paste your text into "Text". The converted text appears in "Result" as you type.
- Click "Copy" to take the result, or "Use result as input" to move it into the input box and convert it again with another setting. "Clear" empties the box.
What it does
Four conversions
Switch between full-width and half-width forms in either direction, or between hiragana and katakana.
Choose what changes
Switch letters, digits, symbols, spaces and katakana on or off, so a conversion touches only the characters you pick.
Voiced marks handled
Katakana with voiced marks converts as a unit: ガ becomes ｶﾞ and パ becomes ﾊﾟ, and the other way round.
Live results
The result updates while you type or paste, with no convert button to press.
Chain conversions
"Use result as input" sends the result back to the input, so you can run a second conversion on it.
Settings remembered
Your last text and settings are kept in this browser, so a refresh does not lose them.
Good to know
East Asian text uses full-width characters, which are as wide as a Japanese character: Ａ, １, ！ and ア are full-width. ASCII characters, the letters, digits and symbols of plain English text, are half-width, and so is half-width katakana such as ｱ. The two forms look alike, but they are different characters, so a full-width １ and a half-width 1 can fail to match in a search, a sort or a form check.
Typical jobs are a form that demands half-width digits or full-width katakana, data that needs cleaning before it goes into a spreadsheet, and text where full-width and half-width spaces are mixed. Pick only the kinds of characters you need: with just "Digits" ticked, letters, symbols and spaces stay as they are. In a width conversion kanji and hiragana are not touched, and the two kana modes convert only hiragana and katakana.
Questions and answers
What is the difference between full-width and half-width characters?
Full-width characters take the width of a typical Japanese character, while half-width ones, such as ASCII letters and digits and half-width katakana, are about half as wide. Both forms exist for letters, digits, symbols, spaces and katakana.
How do I convert full-width numbers to half-width numbers?
Choose "Full-width → half-width" and keep "Digits" ticked. Untick "Letters", "Symbols", "Spaces" and "Katakana" if only the digits should change.
What happens to half-width katakana such as ｶﾞ?
With "Half-width → full-width", a half-width katakana followed by a voicing mark, such as ｶﾞ, becomes one full-width character (ガ). With "Full-width → half-width", ガ splits into two half-width characters (ｶﾞ).
Can I turn hiragana into katakana?
Yes. Choose "Hiragana → katakana", or "Katakana → hiragana" for the reverse. Kanji and other characters stay as they are.
Can I convert only the spaces?
Yes. Tick only "Spaces" under "Characters to convert". With "Full-width → half-width", full-width spaces then become ordinary spaces and everything else stays as typed.
Is my text saved or uploaded?
The conversion runs in your browser, so nothing is uploaded. Your last text and settings are kept in this browser on this device.