Definition of ASCII in Network Encyclopedia.

What is ASCII?

Acronym for American Standard Code for Information Interchange, a widely accepted system for coding U.S. English text using numeric values. The purpose of ASCII is to allow human readable documents to be stored and processed as binary information by computers.

How this works

ASCII assigns a unique numeric value to each lowercase and uppercase alphabet letter, number, punctuation mark, and to certain other characters. For example, the capital letter “A” has the ASCII code 65, while a blank space has the code 32.

ASCII is a 7-bit character set that is the same as the first 128 characters (numbers 0 to 127) of the ANSI character set. The following table shows the various characters in the ASCII character set. The first 32 characters are nonprinting control characters that can be executed from the keyboard by using the Control key combined with other keys.

The ASCII Character Set

Char	Dec	Oct	Hex	Control Key Combination	Description
NUL	0	0	0	^@	Null character
SOH	1	1	1	^A	Start of heading
STX	2	2	2	^B	Start of text
ETX	3	3	3	^C	End of text
EOT	4	4	4	^D	End of transmission
ENQ	5	5	5	^E	Enquiry
ACK	6	6	6	^F	Acknowledge
BEL	7	7	7	^G	Bell
BS	8	10	8	^H	Backspace
HT	9	11	9	^I	Horizontal tab
LF	10	12	a	^J	Line feed
VT	11	13	b	^K	Vertical tab
FF	12	14	c	^L	Form feed
CR	13	15	d	^M	Carriage return
SO	14	16	e	^N	Shift out
SI	15	17	f	^O	Shift in
DLE	16	20	10	^P	Data link escape
DC1	17	21	11	^Q	Device control 1 (XON)
DC2	18	22	12	^R	Device control 2
DC3	19	23	13	^S	Device control 3 (XOFF)
DC4	20	24	14	^T	Device control 4
NAK	21	25	15	^U	Negative acknowledge
SYN	22	26	16	^V	Synchronous idle
ETB	23	27	17	^W	End transmission block
CAN	24	30	17	^X	Cancel line
EM	25	31	19	^Y	End of medium
SUB	26	32	1a	^Z	Substitute
ESC	27	33	1b	^[	Escape
FS	28	34	1c	^\	File separator
GS	29	35	1d	^]	Group separator
RS	30	36	1e	^^	Record separator
US	31	37	1f	^_	Unit separator
SP	32	40	20		Space
!	33	41	21		Exclamation mark
“	34	42	22		Quotation mark
#	35	43	23		Cross hatch
$	36	44	24		Dollar sign
%	37	45	25		Percent sign
&	38	46	26		Ampersand
‘	39	47	27		Apostrophe
(	40	50	28		Opening parenthesis
)	41	51	29		Closing parenthesis
*	42	52	2a		Asterisk
+	43	53	2b		Plus
,	44	54	2c		Comma
–	45	55	2d		Hyphen
.	46	56	2e		Period
/	47	57	2f		Forward slash
0	48	60	30		Zero
1	49	61	31		One
2	50	62	32		Two
3	51	63	33		Three
4	52	64	34		Four
5	53	65	35		Five
6	54	66	36		Six
7	55	67	37		Seven
8	56	70	38		Eight
9	57	71	39		Nine
:	58	72	3a		Colon
;	59	73	3b		Semicolon
<	60	74	3c		Less than sign
=	61	75	3d		Equals sign
>	62	76	3e		Greater than sign
?	63	77	3f		Question mark
@	64	100	40		At sign
A	65	101	41		Uppercase A
B	66	102	42		Uppercase B
C	67	103	43		Uppercase C
D	68	104	44		Uppercase D
E	69	105	45		Uppercase E
F	70	106	46		Uppercase F
G	71	107	47		Uppercase G
H	72	110	48		Uppercase H
I	73	111	49		Uppercase I
J	74	112	4a		Uppercase J
K	75	113	4b		Uppercase K
L	76	114	4c		Uppercase L
M	77	115	4d		Uppercase M
N	78	116	4e		Uppercase N
O	79	117	4f		Uppercase O
P	80	120	50		Uppercase P
Q	81	121	51		Uppercase Q
R	82	122	52		Uppercase R
S	83	123	53		Uppercase S
T	84	124	54		Uppercase T
U	85	125	55		Uppercase U
V	86	126	56		Uppercase V
W	87	127	57		Uppercase W
X	88	130	58		Uppercase X
Y	89	131	59		Uppercase Y
Z	90	132	5a		Uppercase Z
[	91	133	5b		Opening square bracket
\	92	134	5c		Backslash
]	93	135	5d		Closing square bracket
^	94	136	5e		Caret
_	95	137	5f		Underscore
‘	96	140	60		Opening single quote
a	97	141	61		Lowercase a
b	98	142	62		Lowercase b
c	99	143	63		Lowercase c
d	100	144	64		Lowercase d
e	101	145	65		Lowercase e
f	102	146	66		Lowercase f
g	103	147	67		Lowercase g
h	104	150	68		Lowercase h
i	105	151	69		Lowercase i
j	106	152	6a		Lowercase j
k	107	153	6b		Lowercase k
l	108	154	6c		Lowercase l
m	109	155	6d		Lowercase m
n	110	156	6e		Lowercase n
o	111	157	6f		Lowercase o
p	112	160	70		Lowercase p
q	113	161	71		Lowercase q
r	114	162	72		Lowercase r
s	115	163	73		Lowercase s
t	116	164	74		Lowercase t
u	117	165	75		Lowercase u
v	118	166	76		Lowercase v
w	119	167	77		Lowercase w
x	120	170	78		Lowercase x
y	121	171	79		Lowercase y
z	122	172	7a		Lowercase z
{	123	173	7b		Opening curly brace
|	124	174	7c		Vertical line (pipe)
}	125	175	7d		Closing curly brace
~	126	176	7e		Tilde
DEL	127	177	7f		Delete

TIP: When you download files using File Transfer Protocol (FTP), you can choose whether to transfer the files as binary files or text files (ASCII files). Use only the ASCII file setting when downloading plain text files – otherwise, files will not be correctly transferred.

ASCII is an acronym that stands for American Standard Code for Information Interchange. The ASCII code is used in almost every countries in the world.