Full/Half Width Converter - Free Online Tool | PivaBox

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.

Frequently Asked Questions

What are full-width and half-width characters, and why do both exist in Unicode?

Full-width (全角) and half-width (半角) characters originate from East Asian typography and character encoding history. In traditional Chinese, Japanese, and Korean printing, Chinese characters (CJK ideographs) naturally occupy a square block of space. When Latin letters, numbers, and punctuation needed to be mixed with CJK text, two approaches emerged: half-width characters that retain their natural narrow proportions (like standard ASCII), and full-width variants designed to occupy the same square space as a Chinese character for visual rhythm and alignment. Unicode preserves both forms for backward compatibility with legacy encodings like Shift_JIS, GB 2312, and EUC. For example, the letter 'A' exists as both U+0041 (half-width) and U+FF21 (full-width Ａ). The full-width forms in Unicode reside in the Halfwidth and Fullwidth Forms block (U+FF00–U+FFEF). PivaBox converter helps you normalize between these forms quickly and privately.

Why would I need to convert between full-width and half-width characters in practice?

Full/half-width conversion solves several real-world problems: (1) <strong>Programming and databases</strong> — full-width numbers like １２３ or full-width quotation marks like "..." will cause syntax errors in code and CSV parsing failures — converting to half-width fixes these instantly. (2) <strong>Password and form validation</strong> — a user typing their email in a Japanese IME may accidentally produce full-width @ or . characters that fail validation; normalizing to half-width prevents these failures. (3) <strong>Search and matching</strong> — full-width and half-width versions of the same text won't match in string comparison — normalizing ensures consistent results. (4) <strong>Visual consistency</strong> — mixing full and half-width characters in the same line creates uneven spacing — conversion creates clean, professional-looking text. (5) <strong>Character count and length limits</strong> — full-width characters often count as 2 bytes in legacy systems (like SMS messages or older databases) — converting to half-width can help stay within byte limits.

Does the converter handle all Unicode full-width and half-width character pairs correctly?

The PivaBox converter covers the complete set of paired characters between the ASCII range and the Halfwidth and Fullwidth Forms block (U+FF00–U+FFEF), including: all uppercase and lowercase Latin letters (Ａ–Ｚ ↔ A–Z, ａ–ｚ ↔ a–z), digits (０–９ ↔ 0–9), common punctuation (！＂＃＄％＆＇（）＊＋，－．／：；＜＝＞？＠［＼］＾＿｀｛｜｝～), the full-width space (U+3000, the CJK ideographic space), and special cases like the full-width middle dot (・) and wave dash (〜). The tool processes text character by character — characters that don't have a width variant (including CJK ideographs, emoji, and most Unicode symbols) pass through unchanged. All conversion runs entirely in your browser using JavaScript string manipulation — your text never leaves your device, making it safe for sensitive business documents and personal data.