Invisible Character Detector

What Are Invisible Characters?

Invisible characters are Unicode code points that render with zero width or look identical to a normal space. The most common ones are the zero-width space (U+200B), zero-width non-joiner (U+200C), zero-width joiner (U+200D), byte order mark (U+FEFF), no-break space (U+00A0), and soft hyphen (U+00AD). You can't see them, but software can — and that mismatch causes real bugs.

Where Do They Come From?

• Copy-pasting from websites, Word documents, PDFs, or chat apps
• Text exported from CMS editors and rich-text fields
• AI writing tools and translation services
• Files saved with a UTF-8 BOM by Windows editors
• Emoji sequences (which legitimately use zero-width joiners)

Problems They Cause

• Broken code — a zero-width space inside a variable name or JSON key produces errors that look impossible to debug, because the code looks correct.
• Failed comparisons — "admin" with a hidden character is not equal to "admin", breaking logins, lookups, and deduplication.
• Broken URL slugs — invisible characters inside a slug create URLs that look right but 404.
• SEO and search mismatches — search indexes treat visually identical strings as different.
• CSV/database corruption — a BOM at the start of a file silently shifts the first column name.

How This Tool Works

Paste your text and the detector scans every character against a list of 40+ invisible and zero-width Unicode code points. For each type found you get the exact code point (e.g. U+200B), the official Unicode name, the count, and the first positions in the string. One click produces a cleaned copy — zero-width characters are removed, exotic spaces are normalized to regular spaces, and line/paragraph separators become normal newlines. Scanning runs entirely in your browser; nothing is uploaded.

FAQ

Are zero-width characters always bad?

No. Zero-width joiners are essential in emoji sequences (👨‍👩‍👧 is three emoji joined by ZWJ) and some scripts (Arabic, Indic) use ZWNJ/ZWJ legitimately. This tool shows you what is present so you can decide — it doesn't assume every invisible character is a mistake.

Can this tool detect AI watermarks?

This tool detects Unicode characters, full stop. It reports exactly which code points appear in your text and how many. It makes no claims about where they came from or whether they constitute a watermark.

Is my text sent to a server?

No. All scanning happens locally in your browser.

Related Tools

Read the full background in our guide What Are Zero-Width Characters?. For broader cleanup, the Plain Text Converter strips HTML and formatting too. Clean up typographic dashes with the Em Dash Remover.