Find and Remove Zero-Width Spaces (ZWS)

Zero-Width Spaces: The Invisible Bug

The zero-width space (ZWS, U+200B) is one of the most frustrating characters in Unicode. It takes up absolutely no visible width, meaning it is completely invisible in text editors, terminals, and web browsers — yet it is a real character that affects string comparisons, parsing, and processing.

Where ZWS Characters Come From

• Web page copy-paste: HTML editors and CMS platforms often insert ZWS characters for text shaping and word-break hints.
• Messaging apps: Slack, Discord, Teams, and WhatsApp sometimes insert ZWS in pasted content.
• Internationalization: ZWS is used as a word-break opportunity in scripts without explicit spaces (Thai, Khmer, Myanmar).
• Steganography: ZWS characters can be used to embed hidden information in text (watermarking).
• Rich text editors: WYSIWYG editors insert ZWS to maintain cursor position in empty elements.

How the Visualizer Shows ZWS

Each zero-width space appears as a red [ZWS] marker in the visualization output. The statistics panel shows the total count.

Real-World Problems

// These look identical but are not equal:
const a = "hello";          // clean
const b = "hel\u200Blo";   // ZWS between l and l

a === b  // false!
a.length // 5
b.length // 6

ZWS also breaks:

• URL parsing: A ZWS in a URL makes the URL invalid
• Email addresses: A ZWS in an email causes delivery failure
• JSON keys: Two keys that look identical but differ by a ZWS
• Regex matching: Pattern hello won't match hel\u200Blo
• Database queries: WHERE clause won't find the record

Removing ZWS Characters

In the Clean section, enable the ZWS toggle and click Clean. For a broader cleanup, also enable ZWJ and ZWNJ to remove all zero-width characters at once.