What is the ASCII code for A?

Uppercase A is 65 in decimal (0x41 hex, 0o101 octal, 01000001 binary). Lowercase a is 97, exactly 32 higher, which is why setting or clearing bit 5 (value 32) flips a letter's case. B is 66, C is 67, and so on through Z at 90.

How many characters are in the ASCII table?

Standard ASCII has 128 codes, numbered 0 to 127, because it is a 7-bit code (2⁷ = 128). Of those, 33 are non-printing control characters (0–31 and 127) and 95 are printable, the space, digits, letters and punctuation you can see on screen.

What is the difference between ASCII and extended ASCII?

Standard ASCII is the fixed 7-bit set of 128 codes (0–127) defined by RFC 20. “Extended ASCII” loosely means the 128–255 range that an 8th bit allows, but there is no single standard for it, ISO-8859-1, Windows-1252 and CP437 each map those bytes differently. This tool labels its 128–255 panel as ISO-8859-1 to avoid ambiguity.

What is the ASCII value of a space?

A blank space is code 32 (0x20 hex, 0o40 octal, 00100000 binary). It is the first printable character in the table. Do not confuse it with (a non-breaking space), which is code 160 in ISO-8859-1, not 32.

Is ASCII the same as Unicode?

No, but they line up at the start. The first 128 Unicode code points (U+0000–U+007F) are identical to ASCII, and UTF-8 encodes them as a single byte with the same value. So every ASCII file is already valid UTF-8. Unicode then extends far beyond 127 to cover every writing system and emoji.

How do I convert text to binary with this tool?

Type your text in the “Text → codes” box and choose the Bin output base. Each character is shown as its 8-bit binary code, for example “Hi” becomes 01001000 01101001. Use the copy-all button to grab the whole string for an assignment or a hex/binary editor.

Why do codes 0–31 show letters like HT and ESC instead of a character?

Those are control characters. They trigger actions rather than print a glyph. HT (9) is a horizontal tab, LF (10) is a line feed, CR (13) is a carriage return, and ESC (27) starts terminal escape sequences. The abbreviations and names come straight from RFC 20.

Does this tool send my text to a server?

No. The table is a fixed lookup and both converters run entirely in your browser with plain JavaScript, nothing is uploaded. You can use it offline once the page has loaded, which also keeps pasted data private.

Developer · Reference

ASCII Table & Text Converter

A complete, searchable ASCII chart (0–127) with decimal, hex, octal and binary for every code, plus a two-way converter that turns text into ASCII codes and codes back into text. Control names from RFC 20. Runs in your browser, no signup.

By Induwara Ashinsana· Co-Founder, Ryzera TechnologiesUpdated Jul 10, 2026

ASCII table & converter0–127

Type text to convert to ASCII codes

Try

Codes (copy all)

72 105 33

H=72i=105!=33

Reference table

128 codes

Dec	Hex	Oct	Binary	Char	HTML	Description
0	0x00	0o0	00000000	NUL	—	Null^@
1	0x01	0o1	00000001	SOH	—	Start of Heading^A
2	0x02	0o2	00000010	STX	—	Start of Text^B
3	0x03	0o3	00000011	ETX	—	End of Text^C
4	0x04	0o4	00000100	EOT	—	End of Transmission^D
5	0x05	0o5	00000101	ENQ	—	Enquiry^E
6	0x06	0o6	00000110	ACK	—	Acknowledge^F
7	0x07	0o7	00000111	BEL	—	Bell^G
8	0x08	0o10	00001000	BS	—	Backspace^H
9	0x09	0o11	00001001	HT	—	Horizontal Tab^I
10	0x0A	0o12	00001010	LF	—	Line Feed^J
11	0x0B	0o13	00001011	VT	—	Vertical Tab^K
12	0x0C	0o14	00001100	FF	—	Form Feed^L
13	0x0D	0o15	00001101	CR	—	Carriage Return^M
14	0x0E	0o16	00001110	SO	—	Shift Out^N
15	0x0F	0o17	00001111	SI	—	Shift In^O
16	0x10	0o20	00010000	DLE	—	Data Link Escape^P
17	0x11	0o21	00010001	DC1	—	Device Control 1 (XON)^Q
18	0x12	0o22	00010010	DC2	—	Device Control 2^R
19	0x13	0o23	00010011	DC3	—	Device Control 3 (XOFF)^S
20	0x14	0o24	00010100	DC4	—	Device Control 4^T
21	0x15	0o25	00010101	NAK	—	Negative Acknowledge^U
22	0x16	0o26	00010110	SYN	—	Synchronous Idle^V
23	0x17	0o27	00010111	ETB	—	End of Transmission Block^W
24	0x18	0o30	00011000	CAN	—	Cancel^X
25	0x19	0o31	00011001	EM	—	End of Medium^Y
26	0x1A	0o32	00011010	SUB	—	Substitute^Z
27	0x1B	0o33	00011011	ESC	—	Escape^[
28	0x1C	0o34	00011100	FS	—	File Separator^\
29	0x1D	0o35	00011101	GS	—	Group Separator^]
30	0x1E	0o36	00011110	RS	—	Record Separator^^
31	0x1F	0o37	00011111	US	—	Unit Separator^_
32	0x20	0o40	00100000	␠	—	Space
33	0x21	0o41	00100001	!	—	Exclamation mark
34	0x22	0o42	00100010	"	"	Double quote
35	0x23	0o43	00100011	#	—	Number sign (hash)
36	0x24	0o44	00100100	$	—	Dollar sign
37	0x25	0o45	00100101	%	—	Percent sign
38	0x26	0o46	00100110	&	&	Ampersand
39	0x27	0o47	00100111	'	'	Apostrophe (single quote)
40	0x28	0o50	00101000	(	—	Left parenthesis
41	0x29	0o51	00101001	)	—	Right parenthesis
42	0x2A	0o52	00101010	*	—	Asterisk
43	0x2B	0o53	00101011	+	—	Plus sign
44	0x2C	0o54	00101100	,	—	Comma
45	0x2D	0o55	00101101	-	—	Hyphen-minus
46	0x2E	0o56	00101110	.	—	Full stop (period)
47	0x2F	0o57	00101111	/	—	Slash (solidus)
48	0x30	0o60	00110000	0	—	Digit 0
49	0x31	0o61	00110001	1	—	Digit 1
50	0x32	0o62	00110010	2	—	Digit 2
51	0x33	0o63	00110011	3	—	Digit 3
52	0x34	0o64	00110100	4	—	Digit 4
53	0x35	0o65	00110101	5	—	Digit 5
54	0x36	0o66	00110110	6	—	Digit 6
55	0x37	0o67	00110111	7	—	Digit 7
56	0x38	0o70	00111000	8	—	Digit 8
57	0x39	0o71	00111001	9	—	Digit 9
58	0x3A	0o72	00111010	:	—	Colon
59	0x3B	0o73	00111011	;	—	Semicolon
60	0x3C	0o74	00111100	<	<	Less-than sign
61	0x3D	0o75	00111101	=	—	Equals sign
62	0x3E	0o76	00111110	>	>	Greater-than sign
63	0x3F	0o77	00111111	?	—	Question mark
64	0x40	0o100	01000000	@	—	At sign
65	0x41	0o101	01000001	A	—	Uppercase letter A
66	0x42	0o102	01000010	B	—	Uppercase letter B
67	0x43	0o103	01000011	C	—	Uppercase letter C
68	0x44	0o104	01000100	D	—	Uppercase letter D
69	0x45	0o105	01000101	E	—	Uppercase letter E
70	0x46	0o106	01000110	F	—	Uppercase letter F
71	0x47	0o107	01000111	G	—	Uppercase letter G
72	0x48	0o110	01001000	H	—	Uppercase letter H
73	0x49	0o111	01001001	I	—	Uppercase letter I
74	0x4A	0o112	01001010	J	—	Uppercase letter J
75	0x4B	0o113	01001011	K	—	Uppercase letter K
76	0x4C	0o114	01001100	L	—	Uppercase letter L
77	0x4D	0o115	01001101	M	—	Uppercase letter M
78	0x4E	0o116	01001110	N	—	Uppercase letter N
79	0x4F	0o117	01001111	O	—	Uppercase letter O
80	0x50	0o120	01010000	P	—	Uppercase letter P
81	0x51	0o121	01010001	Q	—	Uppercase letter Q
82	0x52	0o122	01010010	R	—	Uppercase letter R
83	0x53	0o123	01010011	S	—	Uppercase letter S
84	0x54	0o124	01010100	T	—	Uppercase letter T
85	0x55	0o125	01010101	U	—	Uppercase letter U
86	0x56	0o126	01010110	V	—	Uppercase letter V
87	0x57	0o127	01010111	W	—	Uppercase letter W
88	0x58	0o130	01011000	X	—	Uppercase letter X
89	0x59	0o131	01011001	Y	—	Uppercase letter Y
90	0x5A	0o132	01011010	Z	—	Uppercase letter Z
91	0x5B	0o133	01011011	[	—	Left square bracket
92	0x5C	0o134	01011100	\	—	Backslash
93	0x5D	0o135	01011101	]	—	Right square bracket
94	0x5E	0o136	01011110	^	—	Caret (circumflex)
95	0x5F	0o137	01011111	_	—	Underscore
96	0x60	0o140	01100000	`	—	Grave accent (backtick)
97	0x61	0o141	01100001	a	—	Lowercase letter a
98	0x62	0o142	01100010	b	—	Lowercase letter b
99	0x63	0o143	01100011	c	—	Lowercase letter c
100	0x64	0o144	01100100	d	—	Lowercase letter d
101	0x65	0o145	01100101	e	—	Lowercase letter e
102	0x66	0o146	01100110	f	—	Lowercase letter f
103	0x67	0o147	01100111	g	—	Lowercase letter g
104	0x68	0o150	01101000	h	—	Lowercase letter h
105	0x69	0o151	01101001	i	—	Lowercase letter i
106	0x6A	0o152	01101010	j	—	Lowercase letter j
107	0x6B	0o153	01101011	k	—	Lowercase letter k
108	0x6C	0o154	01101100	l	—	Lowercase letter l
109	0x6D	0o155	01101101	m	—	Lowercase letter m
110	0x6E	0o156	01101110	n	—	Lowercase letter n
111	0x6F	0o157	01101111	o	—	Lowercase letter o
112	0x70	0o160	01110000	p	—	Lowercase letter p
113	0x71	0o161	01110001	q	—	Lowercase letter q
114	0x72	0o162	01110010	r	—	Lowercase letter r
115	0x73	0o163	01110011	s	—	Lowercase letter s
116	0x74	0o164	01110100	t	—	Lowercase letter t
117	0x75	0o165	01110101	u	—	Lowercase letter u
118	0x76	0o166	01110110	v	—	Lowercase letter v
119	0x77	0o167	01110111	w	—	Lowercase letter w
120	0x78	0o170	01111000	x	—	Lowercase letter x
121	0x79	0o171	01111001	y	—	Lowercase letter y
122	0x7A	0o172	01111010	z	—	Lowercase letter z
123	0x7B	0o173	01111011	{	—	Left curly brace
124	0x7C	0o174	01111100	\|	—	Vertical bar (pipe)
125	0x7D	0o175	01111101	}	—	Right curly brace
126	0x7E	0o176	01111110	~	—	Tilde
127	0x7F	0o177	01111111	DEL	—	Delete^?

Sources: control names and the 128 code assignments follow RFC 20 and the Unicode U+0000 chart. HTML entities follow the WHATWG named references.

How it works

The table is a fixed lookup, not a guess. The 128 code assignments, control-character abbreviations and control names are transcribed directly from RFC 20, “ASCII format for Network Interchange”, the IETF document that made US-ASCII an Internet Standard (STD 80), and cross-checked against the Unicode Consortium's “C0 Controls and Basic Latin” code chart, which confirms ASCII maps one-to-one onto the first 128 Unicode code points (U+0000–U+007F).

Every derived column is a pure base conversion of the decimal code point n, where 0 ≤ n ≤ 127:

Hexadecimal: n in base 16, upper-cased and 2-padded, 65 → 41.
Octal: n in base 8, 65 → 101.
Binary: n in base 2, zero-padded to 8 bits, 65 → 01000001.

Text → codes:the tool reads your text one Unicode code point at a time (so multi-byte characters and emoji are handled cleanly). If a character's code point is 127 or below it is standard ASCII and is shown in your chosen base; anything above 127 is reported as a U+XXXX Unicode code point and left out of the ASCII code list, because ASCII simply has no code for it.

Codes → text: each token you paste is parsed by its prefix, 0x for hexadecimal, 0b for binary, 0o for octal, otherwise decimal. A whole number in range (0–127, or 0–255 when the extended panel is on) is mapped back to its character; anything non-numeric, fractional or out of range is flagged individually rather than silently dropped.

As a credibility check the page runs a small self-test on load: it re-derives every binary value with an independent bit-mask routine (never toString(2)) and round-trips all 128 codes through the browser's character encoder. The “Self-verified” badge only appears when all of those checks pass. The optional 128–255 panel uses the ISO-8859-1 (Latin-1) mapping, where the code point equals the byte value, and is captioned that “extended ASCII” is code-page dependent, not part of the 7-bit standard.

Worked examples

Text → codes: "Hi!"

H → decimal 72 → hex 0x48 → octal 0o110 → binary 01001000
i → decimal 105 → hex 0x69 → octal 0o151 → binary 01101001
! → decimal 33 → hex 0x21 → octal 0o41 → binary 00100001
Check: 'A' = 65, so 'H' = 65 + 7 = 72 ✓; 'a' = 97, so 'i' = 97 + 8 = 105 ✓
Decimal copy-all string: 72 105 33

Codes → text: mixed bases

Input: 0x48 0x69 32 87 111 114 108 100
0x48 = 72 = 'H', 0x69 = 105 = 'i', 32 = space
87 = 'W', 111 = 'o', 114 = 'r', 108 = 'l', 100 = 'd'
Check: 'W' = 65 + 22 = 87 ✓; 'o' = 97 + 14 = 111 ✓
Decoded text: “Hi World”

Edge cases: what gets rejected

-1 → out of range (below 0), flagged, not decoded
128 with the extended panel off → out of range (max 127)
65.5 → not a valid decimal number (fractional), flagged
1000000000 → out of range (far above 127)
Every bad token is listed separately; valid ones still decode.

Frequently asked questions

Sources & references

The 128 code assignments and control names on this page were last cross-checked against RFC 20 and the Unicode U+0000 chart on 2026-07-10. ASCII is a frozen standard, so these values do not change year to year.

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