ASCII (American Standard Code for Information Interchange) is a character encoding standard that maps 128 characters — including letters, digits, punctuation, and control codes — to integers 0–127.

What are control characters?

Control characters (0–31 and 127) are non-printable characters used for device control and formatting. Common examples include LF (10, line feed), CR (13, carriage return), TAB (9), and ESC (27).

What comes after ASCII?

Unicode extends ASCII with over 140,000 characters covering all modern writing systems. The first 128 code points of UTF-8 are identical to ASCII, making UTF-8 backward compatible.

ASCII Table

Complete ASCII character table with decimal, hex, octal, and binary values for every printable and control character. Free, no sign-up.

128 characters

Dec	Hex	Oct	Bin	Char	Description
0	00	000	00000000	NUL	NUL
1	01	001	00000001	SOH	SOH
2	02	002	00000010	STX	STX
3	03	003	00000011	ETX	ETX
4	04	004	00000100	EOT	EOT
5	05	005	00000101	ENQ	ENQ
6	06	006	00000110	ACK	ACK
7	07	007	00000111	BEL	BEL
8	08	010	00001000	BS	BS
9	09	011	00001001	HT	HT
10	0A	012	00001010	LF	LF
11	0B	013	00001011	VT	VT
12	0C	014	00001100	FF	FF
13	0D	015	00001101	CR	CR
14	0E	016	00001110	SO	SO
15	0F	017	00001111	SI	SI
16	10	020	00010000	DLE	DLE
17	11	021	00010001	DC1	DC1
18	12	022	00010010	DC2	DC2
19	13	023	00010011	DC3	DC3
20	14	024	00010100	DC4	DC4
21	15	025	00010101	NAK	NAK
22	16	026	00010110	SYN	SYN
23	17	027	00010111	ETB	ETB
24	18	030	00011000	CAN	CAN
25	19	031	00011001	EM	EM
26	1A	032	00011010	SUB	SUB
27	1B	033	00011011	ESC	ESC
28	1C	034	00011100	FS	FS
29	1D	035	00011101	GS	GS
30	1E	036	00011110	RS	RS
31	1F	037	00011111	US	US
32	20	040	00100000		Space
33	21	041	00100001	!
34	22	042	00100010	"
35	23	043	00100011	#
36	24	044	00100100	$
37	25	045	00100101	%
38	26	046	00100110	&
39	27	047	00100111	'
40	28	050	00101000	(
41	29	051	00101001	)
42	2A	052	00101010	*
43	2B	053	00101011	+
44	2C	054	00101100	,
45	2D	055	00101101	-
46	2E	056	00101110	.
47	2F	057	00101111	/
48	30	060	00110000	0
49	31	061	00110001	1
50	32	062	00110010	2
51	33	063	00110011	3
52	34	064	00110100	4
53	35	065	00110101	5
54	36	066	00110110	6
55	37	067	00110111	7
56	38	070	00111000	8
57	39	071	00111001	9
58	3A	072	00111010	:
59	3B	073	00111011	;
60	3C	074	00111100	<
61	3D	075	00111101	=
62	3E	076	00111110	>
63	3F	077	00111111	?
64	40	100	01000000	@
65	41	101	01000001	A
66	42	102	01000010	B
67	43	103	01000011	C
68	44	104	01000100	D
69	45	105	01000101	E
70	46	106	01000110	F
71	47	107	01000111	G
72	48	110	01001000	H
73	49	111	01001001	I
74	4A	112	01001010	J
75	4B	113	01001011	K
76	4C	114	01001100	L
77	4D	115	01001101	M
78	4E	116	01001110	N
79	4F	117	01001111	O
80	50	120	01010000	P
81	51	121	01010001	Q
82	52	122	01010010	R
83	53	123	01010011	S
84	54	124	01010100	T
85	55	125	01010101	U
86	56	126	01010110	V
87	57	127	01010111	W
88	58	130	01011000	X
89	59	131	01011001	Y
90	5A	132	01011010	Z
91	5B	133	01011011	[
92	5C	134	01011100	\
93	5D	135	01011101	]
94	5E	136	01011110	^
95	5F	137	01011111	_
96	60	140	01100000	`
97	61	141	01100001	a
98	62	142	01100010	b
99	63	143	01100011	c
100	64	144	01100100	d
101	65	145	01100101	e
102	66	146	01100110	f
103	67	147	01100111	g
104	68	150	01101000	h
105	69	151	01101001	i
106	6A	152	01101010	j
107	6B	153	01101011	k
108	6C	154	01101100	l
109	6D	155	01101101	m
110	6E	156	01101110	n
111	6F	157	01101111	o
112	70	160	01110000	p
113	71	161	01110001	q
114	72	162	01110010	r
115	73	163	01110011	s
116	74	164	01110100	t
117	75	165	01110101	u
118	76	166	01110110	v
119	77	167	01110111	w
120	78	170	01111000	x
121	79	171	01111001	y
122	7A	172	01111010	z
123	7B	173	01111011	{
124	7C	174	01111100	\|
125	7D	175	01111101	}
126	7E	176	01111110	~
127	7F	177	01111111	DEL	DEL

How the ASCII Table tool works

The ASCII table provides an interactive reference for all 128 standard ASCII characters (codes 0–127) and the extended ASCII set (128–255), with each character shown in decimal, hexadecimal, octal, binary, and HTML entity formats. Developers, system administrators, and students use it to look up control characters, escape sequences, and printable symbol codes without memorising the entire table.

Control characters (0–31 and 127)

The first 32 ASCII codes are non-printable control characters, defined alongside the full 128-character set in RFC 20, "ASCII format for Network Interchange". Key ones include: NUL (0) — null terminator in C strings; TAB (9) — horizontal tab; LF (10) — line feed (Unix newline); CR (13) — carriage return (Windows newline uses CR+LF); ESC (27) — escape sequence prefix in ANSI terminal codes; DEL (127) — delete. Understanding these codes is essential for serial terminal debugging and text file parsing.

Printable ASCII characters (32–126)

Characters 32 (space) through 126 (tilde) form the printable ASCII range. This includes uppercase letters A–Z (65–90), lowercase a–z (97–122), digits 0–9 (48–57), and common punctuation. Note the difference between uppercase and lowercase is exactly 32 (0x20) — a single bit flip. This property is exploited in case-insensitive comparisons: clear bit 5 to uppercase, set bit 5 to lowercase.

Extended ASCII (128–255)

Characters 128–255 are not standardised in ASCII itself — they vary by code page. ISO 8859-1 (Latin-1) maps codes 160–255 to accented European characters and symbols like © (169), ® (174), and × (215). Windows-1252 is a superset of Latin-1 that adds curly quotes and em-dashes in the 128–159 range. UTF-8 replaces all extended code pages but is backward-compatible with the 0–127 ASCII range.

Hex and binary lookup for programming

Programmers often need ASCII values in hexadecimal: the digit '0' is 0x30, 'A' is 0x41, 'a' is 0x61. These offsets appear constantly in parsers, compilers, and protocol implementations. The binary representation (e.g., 'A' = 01000001) is useful in bit-manipulation contexts. The table's search and filter functions let you instantly find any character or code without scrolling through all 256 entries.

Frequently asked questions

What is ASCII?: ASCII (American Standard Code for Information Interchange) is a character encoding standard that maps 128 characters — including letters, digits, punctuation, and control codes — to integers 0–127.
What are control characters?: Control characters (0–31 and 127) are non-printable characters used for device control and formatting. Common examples include LF (10, line feed), CR (13, carriage return), TAB (9), and ESC (27).
What comes after ASCII?: Unicode extends ASCII with over 140,000 characters covering all modern writing systems. The first 128 code points of UTF-8 are identical to ASCII, making UTF-8 backward compatible.