1
One
PrintableASCII 49 | Hex 0x31 | U+0031
Digit one at ASCII 49 is the second character in the digit block. In Boolean contexts across most languages, the integer 1 represents true. Confusing the digit 1 with lowercase L (ASCII 108) or uppercase I (ASCII 73) is a classic readability problem that monospace fonts solve by giving each a distinct shape. Binary representation uses only 0 and 1, making these two digits the foundation of all digital computing since Claude Shannon's 1937 thesis linked Boolean algebra to circuit design.
ASCII Code
Decimal
49
Hexadecimal
0x31
Octal
61
Binary
0011 0001
URL Escape
%31
Unicode
Code Point
U+0031
Escape
\u0031
UTF-8 Hex
0x31
UTF-8 Binary
00110001
UTF-16
0x0031
UTF-32
0x00000031
HTML Entities
Numeric
1
Hex
1
How to Type
Windows Alt CodeAlt + 49
HTML Entity
1
Unicode InputU+0031
Source Code Representations
C / Java
"\u0031"CSS
\0031JavaScript
"\u0031"Perl
\x{0031}Python 2
u"\u0031"Python 3
\u0031Ruby
\u{0031}Frequently Asked Questions
What is ASCII code 49?
ASCII code 49 represents the One character. In hexadecimal it is 0x31, in binary 0011 0001, and in octal 61. It is a printable character that appears as "1" in text.
How do I type ASCII 49 on a keyboard?
On Windows, hold Alt and type 49 on the numeric keypad. On Mac, you can use the Character Viewer (Edit > Emoji & Symbols). In HTML, use the entity 1 or 1.