What are the benefits of Full-width / Half-width Converter?

You can quickly remove width inconsistencies that affect search, matching, sorting, and validation.. Half-width katakana combinations with dakuten and handakuten are supported, which fits real Japanese business data.. Selective character type conversion lets you normalize only what you need—adjust alphanumerics while preserving katakana, or vice versa.. Local browser processing keeps sensitive operational text on your machine instead of sending it elsewhere..

Is Full-width / Half-width Converter free?

Yes, it is completely free to use, and no registration is required. Tool processing happens entirely in your browser, and your input content and uploaded files are not sent to a server. Our first-party improvement metrics use no cookies, visitor IDs, or session IDs and store only normalized page paths and daily counts for fixed event IDs.

Full-width / Half-width Converter

Convert alphanumeric text and katakana in either width direction

Japanese Text Utility

Full-width / Half-width Converter

Convert alphanumeric text and katakana between full-width and half-width instantly.

Character types to convert:

Alphanumeric Katakana Space Japanese symbols

Input 0 chars

Result

The converter handles full-width and half-width alphanumerics plus katakana in the browser.

About Full-width / Half-width Converter

Mixed full-width and half-width text is a common source of subtle problems in Japanese workflows. Values that look almost identical can fail equality checks, split search results, break validation rules, or create duplicate records simply because one version uses wide characters and another uses narrow ones. Product codes, campaign labels, kana fields, spreadsheet imports, and copied CRM data are especially prone to this issue.

This converter lets you explicitly choose the direction of conversion so you can normalize text to the format required by your downstream system. Alphanumeric characters are converted efficiently through their code-point relationship, while katakana handling also supports voiced and semi-voiced combinations such as `ｶﾞ` and `ﾊﾟ`. The new character type selection feature lets you convert only alphanumerics, or only katakana, or only spaces—giving you fine-grained control over which elements change while leaving others untouched.

That makes the tool practical for operations teams, marketers, developers, and content editors who need clean Japanese text before import, indexing, or publication. Everything runs locally in the browser, so you can check internal or sensitive text without uploading it.

How to use Full-width / Half-width Converter

Paste text that contains full-width or half-width alphanumerics and katakana into the input area.
Select which character types to convert (alphanumeric, katakana, space, or Japanese symbols). Uncheck any types you want to leave unchanged.
Choose either Full to Half or Half to Full, and the result updates immediately in the output panel.
Copy the normalized text and reuse it in forms, CSV files, product metadata, search terms, or database preparation.

Benefits of Full-width / Half-width Converter

You can quickly remove width inconsistencies that affect search, matching, sorting, and validation.
Half-width katakana combinations with dakuten and handakuten are supported, which fits real Japanese business data.
Selective character type conversion lets you normalize only what you need—adjust alphanumerics while preserving katakana, or vice versa.
Local browser processing keeps sensitive operational text on your machine instead of sending it elsewhere.