> ASCII Table Reference_

Complete ASCII table showing all 128 characters with their decimal, hexadecimal, binary, and octal values.

Control Characters (0-31)

Dec	Hex	Binary	Char	Description
0	00	00000000	NUL	Null
1	01	00000001	SOH	Start of Heading
2	02	00000010	STX	Start of Text
3	03	00000011	ETX	End of Text
4	04	00000100	EOT	End of Transmission
5	05	00000101	ENQ	Enquiry
6	06	00000110	ACK	Acknowledge
7	07	00000111	BEL	Bell
8	08	00001000	BS	Backspace
9	09	00001001	TAB	Horizontal Tab
10	0A	00001010	LF	Line Feed
11	0B	00001011	VT	Vertical Tab
12	0C	00001100	FF	Form Feed
13	0D	00001101	CR	Carriage Return
14	0E	00001110	SO	Shift Out
15	0F	00001111	SI	Shift In
16	10	00010000	DLE	Data Link Escape
17	11	00010001	DC1	Device Control 1
18	12	00010010	DC2	Device Control 2
19	13	00010011	DC3	Device Control 3
20	14	00010100	DC4	Device Control 4
21	15	00010101	NAK	Negative Acknowledge
22	16	00010110	SYN	Synchronous Idle
23	17	00010111	ETB	End of Trans. Block
24	18	00011000	CAN	Cancel
25	19	00011001	EM	End of Medium
26	1A	00011010	SUB	Substitute
27	1B	00011011	ESC	Escape
28	1C	00011100	FS	File Separator
29	1D	00011101	GS	Group Separator
30	1E	00011110	RS	Record Separator
31	1F	00011111	US	Unit Separator

Printable Characters (32-127)

Dec	Hex	Binary	Char
32	20	00100000	SP
33	21	00100001	!
34	22	00100010	"
35	23	00100011	#
36	24	00100100	$
37	25	00100101	%
38	26	00100110	&
39	27	00100111	'
40	28	00101000	(
41	29	00101001	)
42	2A	00101010	*
43	2B	00101011	+
44	2C	00101100	,
45	2D	00101101	-
46	2E	00101110	.
47	2F	00101111	/
48	30	00110000	0
49	31	00110001	1
50	32	00110010	2
51	33	00110011	3
52	34	00110100	4
53	35	00110101	5
54	36	00110110	6
55	37	00110111	7
56	38	00111000	8
57	39	00111001	9
58	3A	00111010	:
59	3B	00111011	;
60	3C	00111100	<
61	3D	00111101	=
62	3E	00111110	>
63	3F	00111111	?
64	40	01000000	@
65	41	01000001	A
66	42	01000010	B
67	43	01000011	C
68	44	01000100	D
69	45	01000101	E
70	46	01000110	F
71	47	01000111	G
72	48	01001000	H
73	49	01001001	I
74	4A	01001010	J
75	4B	01001011	K
76	4C	01001100	L
77	4D	01001101	M
78	4E	01001110	N
79	4F	01001111	O
80	50	01010000	P
81	51	01010001	Q
82	52	01010010	R
83	53	01010011	S
84	54	01010100	T
85	55	01010101	U
86	56	01010110	V
87	57	01010111	W
88	58	01011000	X
89	59	01011001	Y
90	5A	01011010	Z
91	5B	01011011	[
92	5C	01011100	\
93	5D	01011101	]
94	5E	01011110	^
95	5F	01011111	_
96	60	01100000	`
97	61	01100001	a
98	62	01100010	b
99	63	01100011	c
100	64	01100100	d
101	65	01100101	e
102	66	01100110	f
103	67	01100111	g
104	68	01101000	h
105	69	01101001	i
106	6A	01101010	j
107	6B	01101011	k
108	6C	01101100	l
109	6D	01101101	m
110	6E	01101110	n
111	6F	01101111	o
112	70	01110000	p
113	71	01110001	q
114	72	01110010	r
115	73	01110011	s
116	74	01110100	t
117	75	01110101	u
118	76	01110110	v
119	77	01110111	w
120	78	01111000	x
121	79	01111001	y
122	7A	01111010	z
123	7B	01111011	{
124	7C	01111100	\|
125	7D	01111101	}
126	7E	01111110	~
127	7F	01111111	DEL

About ASCII

ASCII (American Standard Code for Information Interchange) was developed in the 1960s and defines 128 characters. Codes 0-31 are control characters, 32-126 are printable characters, and 127 is the delete character. ASCII forms the basis of Unicode and nearly all modern text encoding.

History of ASCII

ASCII was developed by the American Standards Association (now ANSI) and published as a standard in 1963, with significant revisions in 1967 and 1968. It emerged from telegraph code conventions and was designed to enable reliable data exchange between different computer systems and teleprinter equipment at a time when every manufacturer used incompatible character encodings.

The standard encodes 128 characters using 7 bits (values 0–127). The choice of 7 bits was a compromise: it allowed the eighth bit to be used as a parity check bit for error detection over noisy telephone lines, which was critical for early modem communications. IBM's popular extended ASCII used all 8 bits to add 128 additional characters (codes 128–255), including line-drawing characters, accented letters, and graphical symbols — but these extensions were never standardised and varied between manufacturers.

Control Characters (Codes 0–31)

The first 32 ASCII codes are non-printing control characters inherited from teleprinter conventions. Many are now obsolete, but several remain in active use today:

NUL (0) — the null character, used as a string terminator in C and many other programming languages.
TAB (9) — horizontal tab, still widely used for indentation in code and data files.
LF (10) — line feed, the newline character on Unix and macOS systems. Python, Linux shell scripts, and most internet protocols use LF to end lines.
CR (13) — carriage return. Windows uses CR+LF (codes 13+10) to end text lines, which is why cross-platform text files sometimes show unexpected line endings.
ESC (27) — escape, used to begin terminal escape sequences that control cursor movement, colour, and text formatting in terminal emulators.
DEL (127) — technically a control character despite its position at the end of the table. Originally used to "delete" punched tape by overwriting a character with all ones (1111111).

ASCII and Unicode

ASCII's 128 characters are a strict subset of Unicode. The first 128 Unicode code points (U+0000 through U+007F) are identical to ASCII, meaning any valid ASCII text is also valid UTF-8, the most widely used Unicode encoding on the web. UTF-8 was specifically designed this way to ensure backward compatibility: a US English text file in ASCII and the same file in UTF-8 are byte-for-byte identical.

Unicode extends far beyond ASCII's 128 characters to over 149,000 characters covering 161 scripts, mathematical symbols, emoji, and historical writing systems. But every modern programming language, database, operating system, and network protocol that handles text ultimately builds on the ASCII foundation established in the 1960s.

ASCII vs Latin-1 vs UTF-8

Several encodings extend ASCII in different directions. Latin-1 (ISO 8859-1) uses 8 bits to add 128 Western European characters (accented letters like é, ü, ñ) in the 128–255 range. Windows-1252 is a Microsoft extension of Latin-1. UTF-8 uses variable-length encoding (1–4 bytes per character) to represent all of Unicode while keeping ASCII characters as single bytes. For new software, UTF-8 is the correct choice; Latin-1 and Windows-1252 are legacy encodings that cause mojibake (garbled text) when mixed.

Frequently Asked Questions

What is ASCII code 32?

ASCII code 32 is the space character (SP). It is the first printable ASCII character and the only whitespace character in the printable range.

What is the ASCII code for A?

Uppercase A is ASCII code 65 (hexadecimal 41). Lowercase a is code 97 (hexadecimal 61). The difference between uppercase and lowercase letters is always 32, which corresponds to flipping bit 5.

Why does ASCII only go to 127?

ASCII uses 7 bits (2⁷ = 128 values, 0–127). The eighth bit was reserved for parity error checking in serial communications. When 8-bit systems became standard, the extra 128 codes were used for extended character sets, but these were never universally standardised.