This page finds U+3164 HANGUL FILLER (and its halfwidth sibling U+FFA0) — the blank character behind invisible usernames — and removes it. The sample "empty" name below is not empty. Everything runs in your browser — nothing is uploaded.
A character from the Korean compatibility block that renders as a blank the width of a Hangul syllable — visually indistinguishable from a space, but not classified as whitespace. Which is precisely why the internet adopted it as the "invisible character".
"Invisible character" and "blank name" generator sites hand it out for making empty-looking usernames in games (Among Us made it famous), blank Discord and WhatsApp messages, and empty-looking Instagram captions and TikTok comments. It can also arrive legitimately from Korean IME edge cases.
Validation: it defeats "field required" and trim().length > 0 checks because trim doesn't touch it — it isn't whitespace. Moderation and deduplication: two "blank" names can be different strings. Search: a name you can't see is a name you can't type. And any pipeline that assumes visible-or-whitespace chokes quietly on it.
VS Code: regex-search [\u3164\uffa0]. Command line: grep -rP '[\x{3164}\x{FFA0}]' . — or paste the suspect text above: each filler is flagged (HF) and removed from the cleaned output. If you run a service, reject or normalize these in usernames server-side; client-side checks won't see them.
Guides for the common cleanup jobs — what the source puts into your text, exactly what it breaks, and the tool preloaded with a demonstration:
AI-generated text · Text copied from Word / Google Docs · Text copied from a PDF · Pasted code that won’t run · CSV & spreadsheet data · Invisible watermarks · Many files at once (batch)
Dedicated pages for the usual suspects — what each one is, where it sneaks in from, the exact errors it causes, and how to find it in your editor:
Zero-width space (U+200B) · Non-breaking space (U+00A0) · Byte order mark (BOM) (U+FEFF) · Soft hyphen (U+00AD) · Smart quotes · Em dash (U+2014) · Narrow no-break space (U+202F) · Ideographic space (U+3000) · Zero-width joiner (U+200D) · Zero-width non-joiner (U+200C) · Word joiner (U+2060) · Right-to-left override (U+202E) · Left-to-right mark (U+200E) · Line separator (U+2028) · Variation selector-16 (U+FE0F) · Object replacement character (U+FFFC) · Hangul filler (U+3164) · Braille pattern blank (U+2800) · Ligatures · Minus sign (U+2212)
Страницы на русском — те же инструменты с переведёнными правилами и примерами под задачу:
Невидимые символы в тексте · Убрать невидимые символы · Почистить текст нейросети · Неразрывные пробелы в числах · Текст из Word · Код не запускается