Full/Half Width Converter

Convert between full-width and half-width characters for punctuation, letters, and numbers

Full/Half Width Character Converter — Convert Between Zenkaku (全角) and Hankaku (半角) for CJK Typography, Code Formatting, and Data Normalization

  1. Paste or type your mixed-width text into the input area. Full-width (全角, zenkaku) characters occupy two character cells in monospace typography and are standard in Chinese, Japanese, and Korean (CJK) text environments, while half-width (半角, hankaku) characters occupy one cell and are the default in Western/Latin text. Mixed-width text is a common problem when copying content between CJK and English applications — for example, １２３ (full-width numbers) vs 123 (half-width numbers), or ＡＢＣ (full-width letters) vs ABC (half-width letters). This tool normalizes all character widths based on your preferences.
  2. Choose your conversion direction: Half → Full expands narrow characters to their wide equivalents (ideal for inserting Latin text into CJK documents where visual alignment matters), Full → Half shrinks wide characters to narrow form (essential for code formatting and database fields where full-width characters cause errors), or Toggle to flip every character's width — full becomes half and vice versa. Then select which character categories to convert using the checkboxes: Punctuation (。→｡ ！→! 「→｢), Letters (Ａ→A ａ→a), Numbers (１２３→123), and Spaces (full-width space U+3000 → half-width space U+0020). You can combine any subset of these categories for precise control.
  3. Click Convert to transform your text instantly, then review the result and click Copy to transfer it to your clipboard. Common use cases include: normalizing Japanese user input where IME (Input Method Editor) may produce mixed full/half-width katakana; preparing CSV data for import where full-width commas break field parsing; formatting code comments that contain CJK characters; cleaning up copy-pasted text from PDF documents which often contain full-width alphanumerics; and ensuring consistent visual alignment in bilingual UI layouts. All conversion is done locally in your browser with zero server involvement.

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