U+2081 "₁" Subscript One Unicode Character
Unicode Version 17.0
₁
U+2081 "₁" Subscript One is a numeric glyph designed for use in mathematical and scientific notation, where it appears as a smaller, lowered version of the digit one to indicate a subscript position, such as in chemical formulas like H₂O (where the two is a subscript) or in mathematical expressions like x₁. It belongs to the Superscripts and Subscripts Unicode block and is distinct from the regular digit one, allowing for precise rendering in digital text without requiring font-specific styling. This character ensures consistent representation across platforms for indices, variables, and other technical contexts where subscript numerals are needed.
General Properties
| Code Point | U+2081 |
| Version Added | 1.1 |
| Name | Subscript One |
| Unicode 1.0 Name | Subscript Digit One |
| Block | Superscripts and Subscripts |
| General Category | Other Number |
| Canonical Combining Class | Not Reordered |
| Bidirectional Class | European Number |
| Decomposition Type | Sub |
| Decomposition Mapping | "1" U+0031 Digit One |
Encodings
| HTML Decimal Encoding | ₁ |
| HTML Hex Encoding | ₁ |
| UTF-8 Encoding | 0xE2 0x82 0x81 |
| UTF-16 Encoding | 0x2081 |
| UTF-32 Encoding | 0x00002081 |
| C/C++/Java Escape | \u2081 |
Unicode Properties
| NFC Quick Check | Yes |
| NFD Quick Check | Yes |
| Numeric Type | Digital |
| Numeric Value | 1 |
| Line Break | Ambiguous (Alphabetic or Ideographic) |
| East Asian Width | Ambiguous |
| Changes When NFKC Casefolded | Yes |
| NFKC Casefold | "1" U+0031 Digit One |
| NFKC Simple Casefold | "1" U+0031 Digit One |
| Script | Common |
| Script Extensions | Common |
| Indic Syllabic Category | Other |
| ID Compat Math Continue | Yes |
| Vertical Orientation | Rotated |
| Grapheme Base | Yes |
| Grapheme Cluster Break | Other |
| Word Break | Other |
| Sentence Break | Other |