ASCII stands for the American Standard Code for Information Interchange. ASCII was the first character set (encoding standard) used between computers on the Internet. Both ISO-8859-1 (default in HTML 4.01) and UTF-8 (default in HTML5), are built on ASCII. The character encoding for the early web was ASCII. Later, from HTML 2.0 to HTML 4.01, ISO-8859-1 was considered the standard. It was designed in the early 60's, as a standard character set for computers and electronic devices.

Binary Information

Computer information (numbers, texts and pictures) is stored as binary ones and zeros (01000101) in the electronics. To standardize the storing of alphanumeric characters, the American Standard Code for Information Interchange (ASCII) was created. It defined a unique binary 7-bits number for each character.

Number of Characters in ASCII

27 = 128

ASCII is a 7-bit character set containing 128 characters. It contains the numbers from 0-9, the upper and lower case English letters from A to Z, and some special characters.

Since ASCII used one byte (7 bits for the character and one bit for transmission parity control), it could only represent 128 different characters. In addition, 32 of these characters were reserved for other control purposes. The biggest weakness with ASCII was that it excluded non English letters.

ASCII Printable Characters

ASCII Characters Description HTML Entity Codes
  space  
! exclamation mark !
" quotation mark "
# number sign #
$ dollar sign $
% percent sign %
& ampersand &
' apostrophe '
( left parenthesis (
) right parenthesis )
* asterisk *
+ plus sign +
, comma ,
- hyphen -
. period .
/ slash /
0 digit 0 0
1 digit 1 1
2 digit 2 2
3 digit 3 3
4 digit 4 4
5 digit 5 5
6 digit 6 6
7 digit 7 7
8 digit 8 8
9 digit 9 9
: colon :
; semicolon &#59;
< less-than &#60;
= equals-to &#61;
> greater-than &#62;
? question mark &#63;
@ at sign &#64;
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 uppercase S &#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;
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;

Device Control Characters

ASCII Characters Description HTML Entity Codes
NUL 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 (ring) &#07;
BS backspace &#08;
HT horizontal tab &#09;
LF line feed &#10;
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;
SYN synchronize &#22;
ETB end transmission 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 (rubout) &#127;