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Full-width & Half-width Converter
Choose the character types you need and convert them between full-width and half-width forms.
How to use
These are example steps; replace the values for your task.
- Choose half-width conversion and enable katakana and numbers.
- Recheck character limits at the destination after converting.
Converted text
0 characters
About this tool
Standardize mixed full-width and half-width text in forms, lists, product data, CSV files, and web copy. Kanji and hiragana remain unchanged, and only the selected character types are converted. Your text is processed only in your browser and is never sent to a server.
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What are zenkaku and hankaku?
In Japanese text and web forms, full-width characters are often called zenkaku and half-width characters hankaku. This converter changes character width, not the language or meaning of your text.
Choose the types a form asks for
For product codes, full-width ＡＢＣ１２３ becomes ABC123 with letters and numbers selected. With katakana enabled, アイウ ⇄ ｱｲｳ works in both directions; voiced kana are handled as pairs when needed.
English letters do not become Japanese kana. This is not translation or romaji-to-katakana conversion. Hiragana and kanji are not converted to a different script. Keep options off for punctuation or spaces that matter to your document, and check the destination form before submitting.
Normalize character width before removing duplicate list entries
Try a use case and check the result
Normalize ASCII letters and digits in product codes, or match a required katakana width. Select the categories that should change.
Try this example replaces the input and settings. Restore previous input returns to the state before the latest example. Normal draft-saving rules apply.
After trying multiple examples, repeat Restore previous input to return to your original input. History is kept only in this page; restore any input you need before closing it.
Product code: letters and digits only
Input and settings
ＡＢＣ－１２３ ガ
Letters: On; Numbers: On; Symbols: Off; Spaces: Off; Katakana: Off; Direction: Half-width
Expected result
ABC－123 ガ. The full-width hyphen, space and katakana remain because their categories are off.
Half-width katakana and voiced marks
Input and settings
ガ１
Letters: Off; Numbers: On; Symbols: Off; Spaces: Off; Katakana: On; Direction: Half-width
Expected result
ｶﾞ1. One ガ becomes two characters, ｶ and ﾞ, changing the output length.
Check why characters remain unchanged
Input and settings
① é 漢字 ー −
Letters: On; Numbers: On; Symbols: On; Spaces: Off; Katakana: Off; Direction: Half-width
Expected result
Unchanged: ① é 漢字 ー −. Circled digits, accented letters, kanji, the prolonged sound mark and mathematical minus are outside the ASCII-width ranges, and katakana conversion is off.
How to read the result
Similar-looking hyphens, minus signs and kana marks are different characters. An unchanged character can be outside the selected categories or conversion table. The converted badge compares positions in the two strings; splitting a voiced mark can shift later positions and increase the badge.
Scope and pitfalls
Check separators and leading zeros against the receiving system’s specification. This does not perform general Unicode normalization, spelling correction or numeric conversion.
Verified with the existing convertWidth for each option set, including preservation of characters outside its ranges.
Continue with the next task
Frequently asked questions
Are kanji and hiragana converted?
No. Only the selected letters, numbers, symbols, spaces, and katakana are converted.
Does it support voiced half-width katakana?
Yes. It supports forms such as ｶﾞ, ﾊﾟ, and ｳﾞ.
Is my text sent to a server?
No. Conversion and draft storage take place only in your current browser.
Convert only the character types your identifiers need
To turn full-width Ａ００１ into half-width A001, select letters and numbers. Leave katakana and symbols unchanged when their form is meaningful in names or identifiers. Width conversion does not also normalize letter case.
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Inputs and storage
Keep a separate copy before clearing or resetting. This browser autosaves entered text. Data is not restored when read 30 days or more after its last save. Clearing site data or storage restrictions may remove it sooner.
Favorites and language preferences are stored separately and may be lost when site data is cleared. Tool resets and site-data deletion do not delete files already downloaded to your device.