ASCII Table Reference

Interactive ASCII character table with decimal, hexadecimal, octal, and binary values. Searchable, filterable, and click-to-copy.

Showing 128 of 128 characters

Dec	Hex	Oct	Binary	Char	Description
0	0x00	000	00000000	^@	NUL (Null)
1	0x01	001	00000001	^A	SOH (Start of Heading)
2	0x02	002	00000010	^B	STX (Start of Text)
3	0x03	003	00000011	^C	ETX (End of Text)
4	0x04	004	00000100	^D	EOT (End of Transmission)
5	0x05	005	00000101	^E	ENQ (Enquiry)
6	0x06	006	00000110	^F	ACK (Acknowledge)
7	0x07	007	00000111	^G	BEL (Bell)
8	0x08	010	00001000	^H	BS (Backspace)
9	0x09	011	00001001	^I	HT (Horizontal Tab)
10	0x0A	012	00001010	^J	LF (Line Feed)
11	0x0B	013	00001011	^K	VT (Vertical Tab)
12	0x0C	014	00001100	^L	FF (Form Feed)
13	0x0D	015	00001101	^M	CR (Carriage Return)
14	0x0E	016	00001110	^N	SO (Shift Out)
15	0x0F	017	00001111	^O	SI (Shift In)
16	0x10	020	00010000	^P	DLE (Data Link Escape)
17	0x11	021	00010001	^Q	DC1 (Device Control 1)
18	0x12	022	00010010	^R	DC2 (Device Control 2)
19	0x13	023	00010011	^S	DC3 (Device Control 3)
20	0x14	024	00010100	^T	DC4 (Device Control 4)
21	0x15	025	00010101	^U	NAK (Negative Acknowledge)
22	0x16	026	00010110	^V	SYN (Synchronous Idle)
23	0x17	027	00010111	^W	ETB (End of Trans. Block)
24	0x18	030	00011000	^X	CAN (Cancel)
25	0x19	031	00011001	^Y	EM (End of Medium)
26	0x1A	032	00011010	^Z	SUB (Substitute)
27	0x1B	033	00011011	^[	ESC (Escape)
28	0x1C	034	00011100	^\	FS (File Separator)
29	0x1D	035	00011101	^]	GS (Group Separator)
30	0x1E	036	00011110	^^	RS (Record Separator)
31	0x1F	037	00011111	^_	US (Unit Separator)

Dec	Hex	Oct	Binary	Char	Description
32	0x20	040	00100000	␣	Space
33	0x21	041	00100001	!	Printable character '!'
34	0x22	042	00100010	"	Printable character '"'
35	0x23	043	00100011	#	Printable character '#'
36	0x24	044	00100100	$	Printable character '$'
37	0x25	045	00100101	%	Printable character '%'
38	0x26	046	00100110	&	Printable character '&'
39	0x27	047	00100111	'	Printable character '''
40	0x28	050	00101000	(	Printable character '('
41	0x29	051	00101001	)	Printable character ')'
42	0x2A	052	00101010	*	Printable character '*'
43	0x2B	053	00101011	+	Printable character '+'
44	0x2C	054	00101100	,	Printable character ','
45	0x2D	055	00101101	-	Printable character '-'
46	0x2E	056	00101110	.	Printable character '.'
47	0x2F	057	00101111	/	Printable character '/'
48	0x30	060	00110000	0	Printable character '0'
49	0x31	061	00110001	1	Printable character '1'
50	0x32	062	00110010	2	Printable character '2'
51	0x33	063	00110011	3	Printable character '3'
52	0x34	064	00110100	4	Printable character '4'
53	0x35	065	00110101	5	Printable character '5'
54	0x36	066	00110110	6	Printable character '6'
55	0x37	067	00110111	7	Printable character '7'
56	0x38	070	00111000	8	Printable character '8'
57	0x39	071	00111001	9	Printable character '9'
58	0x3A	072	00111010	:	Printable character ':'
59	0x3B	073	00111011	;	Printable character ';'
60	0x3C	074	00111100	<	Printable character '<'
61	0x3D	075	00111101	=	Printable character '='
62	0x3E	076	00111110	>	Printable character '>'
63	0x3F	077	00111111	?	Printable character '?'

Dec	Hex	Oct	Binary	Char	Description
64	0x40	100	01000000	@	Printable character '@'
65	0x41	101	01000001	A	Printable character 'A'
66	0x42	102	01000010	B	Printable character 'B'
67	0x43	103	01000011	C	Printable character 'C'
68	0x44	104	01000100	D	Printable character 'D'
69	0x45	105	01000101	E	Printable character 'E'
70	0x46	106	01000110	F	Printable character 'F'
71	0x47	107	01000111	G	Printable character 'G'
72	0x48	110	01001000	H	Printable character 'H'
73	0x49	111	01001001	I	Printable character 'I'
74	0x4A	112	01001010	J	Printable character 'J'
75	0x4B	113	01001011	K	Printable character 'K'
76	0x4C	114	01001100	L	Printable character 'L'
77	0x4D	115	01001101	M	Printable character 'M'
78	0x4E	116	01001110	N	Printable character 'N'
79	0x4F	117	01001111	O	Printable character 'O'
80	0x50	120	01010000	P	Printable character 'P'
81	0x51	121	01010001	Q	Printable character 'Q'
82	0x52	122	01010010	R	Printable character 'R'
83	0x53	123	01010011	S	Printable character 'S'
84	0x54	124	01010100	T	Printable character 'T'
85	0x55	125	01010101	U	Printable character 'U'
86	0x56	126	01010110	V	Printable character 'V'
87	0x57	127	01010111	W	Printable character 'W'
88	0x58	130	01011000	X	Printable character 'X'
89	0x59	131	01011001	Y	Printable character 'Y'
90	0x5A	132	01011010	Z	Printable character 'Z'
91	0x5B	133	01011011	[	Printable character '['
92	0x5C	134	01011100	\	Printable character '\'
93	0x5D	135	01011101	]	Printable character ']'
94	0x5E	136	01011110	^	Printable character '^'
95	0x5F	137	01011111	_	Printable character '_'

Dec	Hex	Oct	Binary	Char	Description
96	0x60	140	01100000	`	Printable character '`'
97	0x61	141	01100001	a	Printable character 'a'
98	0x62	142	01100010	b	Printable character 'b'
99	0x63	143	01100011	c	Printable character 'c'
100	0x64	144	01100100	d	Printable character 'd'
101	0x65	145	01100101	e	Printable character 'e'
102	0x66	146	01100110	f	Printable character 'f'
103	0x67	147	01100111	g	Printable character 'g'
104	0x68	150	01101000	h	Printable character 'h'
105	0x69	151	01101001	i	Printable character 'i'
106	0x6A	152	01101010	j	Printable character 'j'
107	0x6B	153	01101011	k	Printable character 'k'
108	0x6C	154	01101100	l	Printable character 'l'
109	0x6D	155	01101101	m	Printable character 'm'
110	0x6E	156	01101110	n	Printable character 'n'
111	0x6F	157	01101111	o	Printable character 'o'
112	0x70	160	01110000	p	Printable character 'p'
113	0x71	161	01110001	q	Printable character 'q'
114	0x72	162	01110010	r	Printable character 'r'
115	0x73	163	01110011	s	Printable character 's'
116	0x74	164	01110100	t	Printable character 't'
117	0x75	165	01110101	u	Printable character 'u'
118	0x76	166	01110110	v	Printable character 'v'
119	0x77	167	01110111	w	Printable character 'w'
120	0x78	170	01111000	x	Printable character 'x'
121	0x79	171	01111001	y	Printable character 'y'
122	0x7A	172	01111010	z	Printable character 'z'
123	0x7B	173	01111011	{	Printable character '{'
124	0x7C	174	01111100	\|	Printable character '\|'
125	0x7D	175	01111101	}	Printable character '}'
126	0x7E	176	01111110	~	Printable character '~'
127	0x7F	177	01111111	^?	DEL (Delete)

The Complete Guide to ASCII Character Encoding

What Is ASCII?

ASCII, which stands for the American Standard Code for Information Interchange, is a character encoding standard that has been the bedrock of digital communication since its creation in 1963. Developed by the American National Standards Institute (ANSI), ASCII assigns a unique numerical value to 128 characters, including the English alphabet (both uppercase and lowercase), digits 0 through 9, common punctuation marks, and a set of special control characters. This standardized mapping between numbers and characters allows different computers, operating systems, and software applications to exchange text data in a consistent and predictable manner.

The 128 ASCII characters are divided into two main groups: control characters (codes 0-31 and 127) and printable characters (codes 32-126). Control characters were originally designed to manage hardware devices such as printers and teleprinters, and include codes for operations like carriage return, line feed, tab, and bell. While many of these control characters have become obsolete with modern computing, several remain essential — the newline character (LF, code 10), carriage return (CR, code 13), and horizontal tab (HT, code 9) are still used universally in text processing and file formatting across all operating systems.

The Structure of the ASCII Table

The ASCII table is organized in a deliberately logical manner that reflects the binary nature of computing. The printable characters begin at code 32 (the space character) and continue through code 126 (the tilde ~). The uppercase letters A through Z occupy codes 65 through 90, while their lowercase counterparts a through z occupy codes 97 through 122. This arrangement is not coincidental — the difference between an uppercase letter and its lowercase equivalent is exactly 32, which corresponds to a single bit flip in binary (bit 5). This clever design allows programmers to convert between uppercase and lowercase by simply toggling a single bit, an optimization that was particularly valuable in the era of resource- constrained computing.

The digits 0 through 9 occupy codes 48 through 57, which means you can convert a digit character to its numeric value by subtracting 48 (or subtracting the ASCII value of '0'). Punctuation marks and special symbols fill the remaining printable positions, with commonly used characters like the space (32), exclamation mark (33), and at sign (64) placed at memorable positions. Understanding these numerical relationships between characters is valuable for programmers, system administrators, and anyone who works with text data at a low level.

Extended ASCII and Character Set Limitations

While standard ASCII uses 7 bits and defines only 128 characters, the widespread adoption of 8-bit bytes in computer architecture created an opportunity to extend the character set. Extended ASCII uses the full 8-bit byte to represent 256 characters, with codes 128 through 255 providing additional characters beyond the original ASCII specification. However, unlike standard ASCII, there is no single universal extended ASCII standard. Multiple competing extensions were developed, including ISO 8859-1 (Latin-1) for Western European languages, Windows-1252 for the Windows operating system, and various code pages for other language groups.

These competing standards created significant interoperability problems. A text file encoded with one extended ASCII variant would display incorrect characters when opened with a system expecting a different variant. This fragmentation was one of the primary motivations for developing Unicode, which provides a single, universal character encoding capable of representing characters from all writing systems. Despite Unicode's widespread adoption, understanding ASCII remains essential because ASCII forms the foundation of Unicode — the first 128 Unicode code points are identical to ASCII, and the UTF-8 encoding scheme represents ASCII characters with a single byte, ensuring complete backward compatibility.

ASCII in Modern Computing and Programming

Despite being over six decades old, ASCII continues to play a central role in modern computing. Virtually every programming language uses ASCII characters for its syntax, with keywords, operators, and identifiers all composed from the basic ASCII character set. File formats like JSON, CSV, XML, and HTML are fundamentally ASCII-based, using ASCII characters for structural delimiters and markup tags. Network protocols such as HTTP, SMTP, and FTP use ASCII for their command vocabularies and header fields. Even binary protocols often include ASCII-readable magic numbers at the start of files to help identify file types.

In programming, ASCII values are frequently used for character manipulation, input validation, string processing, and sorting algorithms. Understanding the ASCII table helps developers write efficient code for tasks like converting between uppercase and lowercase, validating that input contains only alphanumeric characters, implementing custom sorting logic, parsing formatted text, and building lexical analyzers for compilers and interpreters. Security professionals also rely on ASCII knowledge when analyzing encoded payloads, decoding obfuscated malware, and examining network traffic at the byte level. Whether you are a beginner learning to program or an experienced developer debugging complex systems, a solid understanding of ASCII character encoding is an invaluable tool in your technical toolkit.