Full-width ⇄ Half-width Converter
Convert between full-width (全角) and half-width (半角) letters, digits and katakana, in your browser.
🔒 Runs entirely in your browser. Your input and output are never sent to a server or stored — fully private.
Did this tool help? Tap to react
About this tool
Convert text between full-width (全角) and half-width (半角) forms — letters, numbers, punctuation and katakana. It is handy for cleaning up Japanese and other CJK text, and runs entirely in your browser.
Frequently asked questions
What are full-width and half-width characters?
Full-width characters take up the space of a CJK character (common in Japanese text), while half-width are the standard narrow Latin or katakana forms. Converting between them normalises mixed text.
Is my text sent anywhere?
No. The conversion happens entirely in your browser; nothing is uploaded or stored.