Is there a HTML character that is blank (including no whitespace) on all browsers?

Finding an HTML character that appears completely invisible—with no whitespace or spacing effect—in every browser is surprisingly tricky. Many “blank” characters like spaces, zero-width spaces, or non-breaking spaces may render differently depending on fonts or screen readers, or they might still occupy layout space.

 The best option: Zero-Width Characters

Zero-Width Space (ZWSP)

 Entity: ​ or ​

• Does not take up visible space
  
• Commonly used to control text wrapping
  
• Works in all modern browsers
  

Example:

  Hello​World

Zero-Width Non-Joiner (ZWNJ)

 Entity: ‌ or ‌

Zero-Width Joiner (ZWJ)

 Entity: ‍ or ‍

All three are intended to influence character shaping or text flow—not to display anything.

 Characters to avoid when seeking “true blank”:

  (non-breaking space)

Still creates visible spacing

Normal spaces or tabs

Render inconsistent spacing

Invisible formatting characters

Can be stripped or altered by minifiers or editors

 Important Notes

• These characters are invisible to human eyes, but screen readers may announce them, depending on accessibility settings.
  
• They may still exist in the DOM and affect text processing functions like .length.
  

 Conclusion:

 Yes, HTML does support truly blank characters that don’t create space. The Zero-Width Space (​) is usually the most reliable choice for invisibility across browsers while maintaining layout integrity.