It is a hidden mark. It tells the two symbols on each side to join up and show as one picture.
Technical note: An invisible character that tells software to merge the characters on either side of it into one image. Emoji families and many gestures are built this way.Reviewed by CoolSymbol.now Editorial · August 2, 2026What you need to know
The zero-width joiner is U+200D.
Nothing is broken when a joined emoji splits.
Long before emoji, the joiner controlled how letters connect in scripts such as Arabic and Devanagari.
See real examples in people symbols & body emoji and emoji symbols. For the full lesson, read How to Copy and Paste Symbols Safely.
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What it does
The zero-width joiner is U+200D. It takes no space and draws nothing. Its only job is to say that the characters around it belong together.
Put a woman, a joiner and a rocket next to each other and a supporting system draws one astronaut. A system that does not recognise the sequence draws a woman, then a rocket.
- Invisible and zero-width
- Written as U+200D
- Used in emoji sequences and in Arabic and Indic scripts
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Why sequences fall apart
Nothing is broken when a joined emoji splits. The receiving system simply has no artwork for that combination, so it shows the parts it does understand.
The same text will join up again on a device that knows the sequence.
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The other job it does
Long before emoji, the joiner controlled how letters connect in scripts such as Arabic and Devanagari. That is still its formal purpose, which is why stripping it from text in those languages causes real damage.
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Sources and further reading
This answer was reviewed against current Unicode terminology and the practical guidance below.
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