ASCII 251
Character 251 (û)
Latin-1 Supplement
Latin small letter with diacritic. Used in Northern European alphabets.
Common uses & context
Decimal 251 (0xFB) is Character 251, part of the Latin-1 Supplement (128–255). Latin small letter with diacritic. Used in Northern European alphabets. It renders as 'û' and its binary byte is 11111011.
This is where single-byte ASCII ends and encoding matters. In Latin-1 (ISO-8859-1) 'û' is the single byte 0xFB. In UTF-8 — today's default for the web — the same character is the multi-byte sequence 0xC3 0xBB. Treating a Latin-1 byte as UTF-8 (or vice versa) is the usual reason accented letters and symbols turn into mojibake like é or €. The Unicode code point is U+00FB, and in HTML you can write it as û.
All encodings at a glance
| Decimal | 251 |
| Hexadecimal | 0xFB |
| Octal | 0373 |
| Binary | 11111011 |
| HTML numeric entity | û |
| URL encoding | %FB |
| UTF-8 bytes | 0xC3 0xBB |
Code snippets
JavaScript
String.fromCharCode(251); // "û"
251.toString(16); // "fb"Python
chr(251) # control char û
ord(chr(251)) # 251
hex(251) # '0xfb'HTML
û <!-- numeric entity (no named entity for this character) -->Programming notes
- ▸Single byte 0xFB in Latin-1, but the multi-byte sequence 0xC3 0xBB in UTF-8 — never assume one byte per character above code 127.
- ▸Unicode code point U+00FB; HTML numeric entity û.
- ▸If 'û' shows as mojibake, the encoding declared and the encoding used disagree — align both on UTF-8.
Unicode & UTF-8 note
In Unicode this is U+00FB. In UTF-8 it encodes to the byte sequence 0xC3 0xBB. In legacy Latin-1 (ISO-8859-1) it is a single byte 0xFB, which is why Latin-1 files often appear as mojibake when interpreted as UTF-8.
Frequently asked questions
What character is ASCII code 251?
ASCII code 251 is the character 'û' (Character 251). In hexadecimal it is 0xFB, in octal 0373, and in binary 11111011.
What is 0xFB in ASCII?
Hexadecimal 0xFB equals decimal 251, which is the character 'û' (Character 251). To convert hex to ASCII yourself, read the two hex digits as a base-16 number (0xFB = 251) and look up that code point.
How do I write the character with code 251 in code?
In JavaScript use String.fromCharCode(251); in Python use chr(251); in HTML use the numeric entity û. In a URL it is percent-encoded as %FB, and in UTF-8 it is stored as the byte sequence 0xC3 0xBB.
Is 'û' part of standard ASCII?
No. Standard ASCII covers codes 0–127 only. 'û' is code 251, part of the Latin-1 Supplement (128–255, sometimes called "extended ASCII"). It is a single byte 0xFB in Latin-1 but a multi-byte sequence (0xC3 0xBB) in UTF-8.