ASCII Character Set and HTML Codes

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.

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	;
<	less-than	<
=	equals-to	=
>	greater-than	>
?	question mark	?
@	at sign	@
A	uppercase A	A
B	uppercase B	B
C	uppercase C	C
D	uppercase D	D
E	uppercase E	E
F	uppercase F	F
G	uppercase G	G
H	uppercase H	H
I	uppercase I	I
J	uppercase J	J
K	uppercase K	K
L	uppercase L	L
M	uppercase M	M
N	uppercase N	N
O	uppercase O	O
P	uppercase P	P
Q	uppercase Q	Q
R	uppercase R	R
S	uppercase S	S
T	uppercase T	T
U	uppercase U	U
V	uppercase V	V
W	uppercase W	W
X	uppercase X	X
Y	uppercase Y	Y
Z	uppercase Z	Z
[	left square bracket	[
\	backslash	\
]	right square bracket	]
^	caret	^
_	underscore	_
`	grave accent	`
a	lowercase a	a
b	lowercase b	b
c	lowercase c	c
d	lowercase d	d
e	lowercase e	e
f	lowercase f	f
g	lowercase g	g
h	lowercase h	h
i	lowercase i	i
j	lowercase j	j
k	lowercase k	k
l	lowercase l	l
m	lowercase m	m
n	lowercase n	n
o	lowercase o	o
p	lowercase p	p
q	lowercase q	q
r	lowercase r	r
s	lowercase s	s
t	lowercase t	t
u	lowercase u	u
v	lowercase v	v
w	lowercase w	w
x	lowercase x	x
y	lowercase y	y
z	lowercase z	z
{	left curly brace	{
\|	vertical bar	\|
}	right curly brace	}
~	tilde	~

Device Control Characters

ASCII reserves the first 32 codes for control characters.

ASCII Characters	Description	HTML Entity Codes
NUL	null character
SOH	start of header
STX	start of text
ETX	end of text
EOT	end of transmission
ENQ	enquiry
ACK	acknowledge
BEL	bell (ring)
BS	backspace
HT	horizontal tab
LF	line feed
VT	vertical tab
FF	form feed
CR	carriage return
SO	shift out
SI	shift in
DLE	data link escape
DC1	device control 1
DC2	device control 2
DC3	device control 3
DC4	device control 4
NAK	negative acknowledge
SYN	synchronize
ETB	end transmission block
CAN	cancel
EM	end of medium
SUB	substitute
ESC	escape
FS	file separator
GS	group separator
RS	record separator
US	unit separator
DEL	delete (rubout)