U+21C4 "⇄" Rightwards Arrow over Leftwards Arrow Unicode Character
Unicode Version 17.0
⇄
U+21C4 "⇄" Rightwards Arrow over Leftwards Arrow is a typographic symbol that depicts two horizontal arrows pointing in opposite directions, with the rightward arrow placed above the leftward arrow. It is commonly used in mathematics, chemistry, and formal notation to represent a reversible reaction, a bidirectional exchange, or a cyclical swapping of elements between two states or components. In computing and user interface design, this character can also signify a data transfer or synchronization process that flows in both directions, making it a concise visual shorthand for mutual interaction or equilibrium.
General Properties
| Code Point | U+21C4 |
| Version Added | 1.1 |
| Name | Rightwards Arrow over Leftwards Arrow |
| Unicode 1.0 Name | Right Arrow over Left Arrow |
| Block | Arrows |
| General Category | Other Symbol |
| Canonical Combining Class | Not Reordered |
| Bidirectional Class | Other Neutral |
Encodings
| HTML Decimal Encoding | ⇄ |
| HTML Hex Encoding | ⇄ |
| UTF-8 Encoding | 0xE2 0x87 0x84 |
| UTF-16 Encoding | 0x21C4 |
| UTF-32 Encoding | 0x000021C4 |
| C/C++/Java Escape | \u21c4 |
Unicode Properties
| NFC Quick Check | Yes |
| NFD Quick Check | Yes |
| NFKC Quick Check | Yes |
| NFKD Quick Check | Yes |
| Numeric Type | None |
| Numeric Value | NaN |
| Line Break | Alphabetic |
| Script | Common |
| Script Extensions | Common |
| Indic Syllabic Category | Other |
| Pattern Syntax | Yes |
| Math | Yes |
| Other Math | Yes |
| Vertical Orientation | Rotated |
| Grapheme Base | Yes |
| Grapheme Cluster Break | Other |
| Word Break | Other |
| Sentence Break | Other |