Zero-Width Non-Joiner U+200C

The zero-width non-joiner (ZWNJ, U+200C) does the opposite of the zero-width joiner: it stops two adjacent characters from connecting or forming a ligature. It takes up no space.

Persian (Farsi) writers type it every day, and Persian keyboard layouts give it a dedicated key combination. Outside Persian and Arabic, people use ZWNJ to try for blank YouTube video titles and invisible text on other platforms.

Common Uses

• Persian and Arabic text. ZWNJ lets two letters sit side by side without joining. Persian compound words and some grammatical forms need this boundary.
• Blank YouTube video titles. Paste ZWNJ as a title to try for one that looks empty.
• Devanagari script. ZWNJ blocks conjunct consonants (ligatures) in Hindi, Sanskrit and other Devanagari scripts, so the halant (virama) shows instead.
• Preventing ligatures in typography. For example, to show "fi" as two letters instead of the "fi" ligature.

How to Type

ZWNJ in Persian Typography

Arabic-script letters have up to four forms by position (isolated, initial, medial, final) and connect to their neighbors automatically. Persian compound words need to show where one part ends and the next begins, without a visible space. ZWNJ breaks the connection at that point, so the parts sit close together but don't connect.

Example

The Persian word for "library" (ketab-khaneh) combines "book" + "house." Without ZWNJ, the letters connect across the boundary and it reads as one unit. With ZWNJ, the two parts stay distinct.

YouTube Blank Title Trick

1. Copy the ZWNJ character from the copy button at the top of this page.
2. Go to YouTube Studio and open the video you want to edit.
3. Clear the existing title and paste the ZWNJ character.
4. Save. If YouTube accepts it, the title will appear blank to viewers.

YouTube can change its validation at any time. If ZWNJ stops working, try Zero-Width Space (U+200B) or Hangul Filler (U+3164).

Why ZWNJ Works for YouTube

YouTube requires a non-empty title and likely trims a regular space. ZWNJ is a real character (category Cf), so the title isn't empty, but with zero width it looks blank. YouTube doesn't document this.

Technical Details

• Unicode category: Cf (Format), not a space or letter.
• Width: Zero. No visible glyph.
• Joining behavior: The characters on either side use their non-joining (isolated or final/initial) forms instead of connected forms.
• Line breaking: Does NOT create a line-break opportunity, unlike zero-width space.
• Bidirectional behavior: Bidi class BN (Boundary Neutral), so it does not affect text direction.

In JavaScript:

// Detect ZWNJtext.includes('\u200C')
// Remove all ZWNJ characterstext.replace(/\u200C/g, '')
// ZWNJ is common in Persian text - you may not want to strip it// from user input without understanding the context

Security Considerations

• Internationalized domain name confusion. IDNA2008 allows ZWNJ in domain labels only in specific contexts (for example after a virama or between certain joining letters). Two domains that look identical can differ by a hidden ZWNJ, which enables phishing.
• Email address confusion. Internationalized email addresses can contain ZWNJ, so two addresses can look the same and still differ.
• Text comparison failures. Strings with ZWNJ won't match strings without it, even when they look identical.

ZWNJ vs Similar Characters

ZWNJ says "do not connect these characters." ZWJ says "connect them." See the Zero-Width Joiner page for how ZWJ builds emoji and forces letter connections in Arabic script.