ASCII (American Standard Code for Information Interchange) is a standard character encoding used in telecommunication. The ASCII pronounced ‘ask-ee’, is strictly a seven-bit code based on the English alphabet. ASCII codes are used to represent alphanumeric data. The code was first published as a standard in 1967. it was subsequently updated and published as ANSI X3.4-1968, then as ANSI X3.4-1977, and finally as ANSI X3.4-1986. Since it is a seven-bit code, it can at the most represent 128 characters. it currently defines 95 printable characters including 26 upper case letters (A to Z), 26 lower case letters, 10 numerals (0 to 9), and 33 special characters including mathematical symbols, punctuation marks and space characters. They represent text in, telecommunications equipment, and devices. These include numbers, upper and lowercase English letters, functions, punctuation symbols, and some other symbols. In total, there are 256 ASCII characters, and can be broadly divided into three categories:
- ASCII control characters (0-31 and 127)
- ASCII printable characters (32-126) (most commonly referred to)
- Extended ASCII characters (128-255)
Below are the ASCII values of printable characters (33, 126):,
Character |
Character Name |
ASCII code |
! |
Exclamation point |
33 |
“ |
Double quotation |
34 |
# |
Number sign |
35 |
$ |
Dollar sign |
36 |
% |
Percent sign |
37 |
& |
ampersand |
38 |
‘ |
apostrophe |
39 |
( |
Left parenthesis |
40 |
) |
Right parenthesis |
41 |
* |
asterisk |
42 |
+ |
Plus sign |
43 |
, |
comma |
44 |
– |
hyphen |
45 |
. |
period |
46 |
/ |
slash |
47 |
0 |
zero |
48 |
1 |
one |
49 |
2 |
two |
50 |
3 |
three |
51 |
4 |
four |
52 |
5 |
five |
53 |
6 |
six |
54 |
7 |
seven |
55 |
8 |
eight |
56 |
9 |
nine |
57 |
: |
colon |
58 |
; |
semi-colon |
59 |
< |
Less-than sign |
60 |
= |
Equals sign |
61 |
> |
Greater-than sign |
62 |
? |
Question mark |
63 |
@ |
At sign |
64 |
Character |
Character Name |
ASCII code |
A |
Uppercase a |
65 |
B |
Uppercase b |
66 |
C |
Uppercase c |
67 |
D |
Uppercase d |
68 |
E |
Uppercase e |
69 |
F |
Uppercase f |
70 |
G |
Uppercase g |
71 |
H |
Uppercase h |
72 |
I |
Uppercase i |
73 |
J |
Uppercase j |
74 |
K |
Uppercase k |
75 |
L |
Uppercase l |
76 |
M |
Uppercase m |
77 |
N |
Uppercase n |
78 |
O |
Uppercase o |
79 |
P |
Uppercase p |
80 |
Q |
Uppercase q |
81 |
R |
Uppercase r |
82 |
S |
uppercases |
83 |
T |
Uppercase t |
84 |
U |
Uppercase u |
85 |
V |
Uppercase v |
86 |
W |
Uppercase w |
87 |
X |
Uppercase x |
88 |
Y |
Uppercase y |
89 |
Z |
Uppercase z |
90 |
[ |
Left square bracket |
91 |
\ |
backslash |
92 |
] |
Right square bracket |
93 |
^ |
caret |
94 |
_ |
underscore |
95 |
` |
Grave accent |
96 |
Character |
Character Name |
ASCII code |
a |
Lowercase a |
97 |
b |
Lowercase b |
98 |
c |
Lowercase c |
99 |
d |
Lowercase d |
100 |
e |
Lowercase e |
101 |
f |
Lowercase f |
102 |
g |
Lowercase g |
103 |
h |
Lowercase h |
104 |
i |
Lowercase i |
105 |
j |
Lowercase j |
106 |
k |
Lowercase k |
107 |
l |
Lowercase l |
108 |
m |
Lowercase m |
109 |
n |
Lowercase n |
110 |
o |
Lowercase o |
111 |
p |
Lowercase p |
112 |
q |
Lowercase q |
113 |
r |
Lowercase r |
114 |
s |
Lowercase s |
115 |
t |
Lowercase t |
116 |
u |
Lowercase u |
117 |
v |
Lowercase v |
118 |
w |
Lowercase w |
119 |
x |
Lowercase x |
120 |
y |
Lowercase y |
121 |
z |
Lowercase z |
122 |
{ |
Left curly brace |
123 |
| |
Vertical bar |
124 |
} |
Right curly brace |
125 |
~ |
tilde |
126 |
So what’s before 33 and beyond 126?
- ASCII values before 32 (0-31) are control characters. A character code is often used in in-band signaling as a reference point in a set of characters to avoid adding additional symbols to the text.
- At 32, we have space, which is included as printed characters, however, it’s not wrong to say space could also serve as a control character.
- At 127, we have DEL (delete), which is a control character.
- After 127, (128-255), we have Extended ASCII characters representing mathematical and other symbols that are not represented as keys and are not used in general.
Below are the ASCII values of control characters (0-31, 127):
Character |
Character Name |
ASCII Code |
NULL |
Null character |
00 |
SOH |
Start of header |
01 |
STX |
Start of text |
02 |
ETX |
End of text |
03 |
EOT |
End of transmission |
04 |
ENQ |
enquiry |
05 |
ACK |
acknowledge |
06 |
BEL |
bell |
07 |
BS |
backspace |
08 |
HT |
Horizontal tab |
09 |
LF |
Line feed |
10 |
Character |
Character Name |
ASCII Code |
VT |
Vertical tab |
11 |
FF |
Form feed |
12 |
CR |
Carriage return |
13 |
SO |
Shift out |
14 |
SI |
Shift in |
15 |
DLE |
Data link escape |
16 |
DC1 |
Device control 1 |
17 |
DC2 |
Device control 2 |
18 |
DC3 |
Device control 3 |
19 |
DC4 |
Device control 4 |
20 |
NAK |
Negative acknowledge |
21 |
Character |
Character Name |
ASCII Code |
SYN |
Synchronous idle |
22 |
ETB |
End of trans. Block |
23 |
CAN |
Cancel |
24 |
EM |
End of medium |
25 |
SUB |
substitute |
26 |
ESC |
escape |
27 |
FS |
File separator |
28 |
GS |
Group separator |
29 |
RS |
Record separator |
30 |
US |
Unit separator |
31 |
DEL |
delete |
127 |
Last Updated :
23 May, 2023
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