Zero Width Character

Zero Width Space Generator — Hidden Unicode Spaces

The Zero Width Space Generator is an online layout and coding utility designed to produce non-printing character overlays that occupy no visual width on screen. Commonly used by programmers to control line breaks in code blocks, emoji designers to link character strings, and security professionals to embed hidden tracking variables (watermarks) in document copy, this generator copies zero-width control characters directly to your clipboard.

How the Zero-Width Character Substitution Works

The formatting script runs locally in the client browser, compiling sequences of specific non-printing characters based on the count setting (defined in the zero-width case in transformers.ts):

1. Zero-Width Space (zwsp): Maps to the code point U+200B (​). This character has zero horizontal width, making it completely invisible on screen, but it registers as a valid character point in text editors and input fields.
2. Zero-Width Joiner (zwj): Maps to U+200D (‍). This control character is used to combine adjacent characters (like rendering compound emojis).
3. Zero-Width Non-Joiner (zwnj): Maps to U+200C (‌). It prevents adjacent characters from automatically ligating or combining.
4. Invisible Separator (separator): Maps to U+2063 (⁣).
5. Word Joiner (wordJoiner): Maps to U+2060 (⁠), which behaves like a zero-width space but prevents line breaks.

If an input string is provided, the engine inserts the padding character after each letter ([...text].map((c) => c + padding).join("")); if no text is entered, it returns only the blank padding sequence.

Differentiation: Zero-Width Space vs. Invisible Character

While both tools generate non-printing spaces, their application contexts differ:

• Zero-Width Space: Focuses on hidden steganography characters (like ZWJ, ZWNJ, and ZWSP) that are completely widthless. They are used in programming, emoji composition, and embedding hidden tracking variables inside text blocks.
• Invisible Character: Focuses on copying blank space fillers (such as Hangul Filler U+3164 or thin space blocks) to bypass form validation constraints. It is used to submit blank forms, create empty status rows, and clear default usernames.

Technical Applications & Steganography

• Line-Breaking Control: In web typography, inserting a zero-width space inside long words or URLs tells the browser's rendering engine that a line break is permitted at that specific point, preventing layout overflow in responsive designs.
• Emoji Ligatures: Emojis representing groups or occupations are often composed of multiple separate emojis joined by a Zero-Width Joiner. For example, the family emoji is a sequence of individual person emojis linked by U+200D control characters.
• Text Watermarking (Steganography): By converting binary messages into sequences of zero-width spaces and zero-width non-joiners, users can hide invisible messages inside standard text blocks. This is used to track leaks in document drafts.

Related Tools

• invisible-character — Generate blank characters to bypass username and message validations.
• space-remover — Remove extra spaces, trim whitespace, or replace spaces with dashes.
• character-counter — Count visual characters, words, paragraphs, and raw byte sizes.