Full-width ↔ Half-width Converter
Normalize text by converting full-width/half-width characters in bulk.
Conversion Options
Symbol Normalization
How to Use
Paste Your Text
Paste the text into the input box (the output updates automatically as you type).
Choose Rules
Pick only what you need: width conversion, space cleanup, and symbol normalization.
Copy the Result
Click "Convert" if needed, then use "Copy" to paste into your destination.
バラバラの全角英数字を「半角」へ一括変換
資料や名簿などに混在する全角の「１２３」や「ＡＢＣ」を、ワンクリックでスッキリとした半角文字に統一。さらに読みにくい半角カタカナを全角カタカナに戻すことで、データベース等に文字列を登録する前の準備時間を大幅に短縮できます。
連続する不要な空白スペースを自動で削除してスッキリ整形
コピペした文章に潜む予期せぬ多重スペースや、行頭・行末の無駄な空白など、見栄えを損ねたり検索漏れの原因となったりする厄介な「空白」をツールが自動検知。ワンボタンでテキストを最適な形にシェイプアップします。
全角スペースと半角スペースをワンクリックで揃える
日本語に混じった全角スペースをWebシステムのバリデーションで弾かれないよう半角に統一したり、逆に読みやすく全角に整列したりと、スペースの種類をコントロール。さらに厄介なハイフンや波ダッシュの違いも同時に解決できます。
FAQ
Is my text sent to a server?
No. Conversion runs in your browser, and your text is not sent anywhere.
What’s the difference between full-width and half-width?
Full-width characters are wider (e.g., ＡＢＣ) and common in Japanese text, while half-width are narrower (ABC). Many systems prefer half-width for consistent input and search.
What exactly gets converted?
It focuses on full-width alphanumerics → half-width, half-width Katakana → full-width, and full-width spaces → half-width. Optional space cleanup and symbol normalization are available; Kanji/Hiragana are left as-is.
Why normalize hyphens or wave dashes?
Lookalike symbols can be different characters, which breaks searching and comparisons. Normalizing them helps avoid subtle mismatches.
Can I use this before pasting into Excel?
Yes. Normalizing width and spaces before CSV/Excel input helps with search, sorting, and deduplication.
Why convert half-width Katakana to full-width?
Half-width Katakana can render inconsistently depending on fonts and systems. Converting to full-width improves consistency and searchability.
Why do symbols change in width conversion?
Unicode compatibility mappings can replace symbols with equivalent code points. If you’re pasting into another system, validate with sample text first.
Is random string strength sufficient?
It depends. Great for test data and placeholder IDs, but for auth tokens/passwords you should choose length/charset/generation method based on your security requirements.
References
- Unicode Standard
Normative source for character systems and code points.
- Unicode UAX #15 (Normalization)
Official normalization behavior reference.
- WHATWG Encoding Standard
Standard for text encoding behavior in browsers.
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