U+0401 "Ё" Cyrillic Capital Letter Io Unicode Character
Unicode Version 17.0
Ё
U+0401 "Ё" Cyrillic Capital Letter Io is a distinct letter in the Cyrillic script, formed by placing a diaeresis or two dots over the letter Е. It represents the sound /jo/ in Russian and other Slavic languages, much like the English “yo” in “yonder.” Although often considered a separate letter in the alphabet, it is sometimes treated as a variant of Е in certain contexts, and its mandatory use in writing can vary by language and style. This character is encoded with a single code point rather than as a combination of Е and the diaeresis combining mark, ensuring it functions as an independent typographical unit.
General Properties
| Code Point | U+0401 |
| Version Added | 1.1 |
| Name | Cyrillic Capital Letter Io |
| Block | Cyrillic |
| General Category | Uppercase Letter |
| Canonical Combining Class | Not Reordered |
| Bidirectional Class | Left To Right |
| Decomposition Type | Canonical |
| Decomposition Mapping | "Е" U+0415 Cyrillic Capital Letter Ie "̈" U+0308 Combining Diaeresis |
Encodings
| HTML Decimal Encoding | Ё |
| HTML Hex Encoding | Ё |
| UTF-8 Encoding | 0xD0 0x81 |
| UTF-16 Encoding | 0x0401 |
| UTF-32 Encoding | 0x00000401 |
| C/C++/Java Escape | \u0401 |
Unicode Properties
| NFC Quick Check | Yes |
| NFKC Quick Check | Yes |
| Numeric Type | None |
| Numeric Value | NaN |
| Line Break | Alphabetic |
| East Asian Width | Ambiguous |
| Uppercase | Yes |
| Simple Lowercase Code Point | "ё" U+0451 Cyrillic Small Letter Io |
| Lowercase Code Point | "ё" U+0451 Cyrillic Small Letter Io |
| Simple Case Folding | "ё" U+0451 Cyrillic Small Letter Io |
| Case Folding | "ё" U+0451 Cyrillic Small Letter Io |
| Cased | Yes |
| Changes When Casefolded | Yes |
| Changes When Casemapped | Yes |
| Changes When Lowercased | Yes |
| Changes When NFKC Casefolded | Yes |
| NFKC Casefold | "ё" U+0451 Cyrillic Small Letter Io |
| NFKC Simple Casefold | "ё" U+0451 Cyrillic Small Letter Io |
| Script | Cyrillic |
| Script Extensions | Cyrillic |
| Indic Syllabic Category | Other |
| ID Start | Yes |
| XID Start | Yes |
| ID Continue | Yes |
| XID Continue | Yes |
| Alphabetic | Yes |
| Vertical Orientation | Rotated |
| Grapheme Base | Yes |
| Grapheme Cluster Break | Other |
| Word Break | Alphabetic letter |
| Sentence Break | Upper |