Question 1

How do I read a hex code like 0x72 as an ASCII character?

Accepted Answer

The prefix 0x marks a hexadecimal number. 0x72 is 7 · 16 + 2 = 114 in decimal, and ASCII character 114 is the lowercase r. Likewise 0x47 is the uppercase G and 0x25 the percent sign. The search above takes hex codes with 0x directly.

Question 2

How many characters does ASCII have?

Accepted Answer

ASCII has 128 characters with the codes 0 to 127, that is 7 bits. 33 of them are control characters (0 to 31 and 127), the other 95 are printable: the space, digits, upper and lower case letters and punctuation.

Question 3

What is the difference between ASCII and UTF-8?

Accepted Answer

UTF-8 encodes the first 128 characters exactly like ASCII with one byte, so every ASCII text is also valid UTF-8. All other Unicode characters, including umlauts and emoji, take two to four bytes in UTF-8.

Dec	Hex	Char	Dec	Hex	Char	Dec	Hex	Char	Dec	Hex	Char
0	0x00	NUL	32	0x20	SP	64	0x40	@	96	0x60	`
1	0x01	SOH	33	0x21	!	65	0x41	A	97	0x61	a
2	0x02	STX	34	0x22	"	66	0x42	B	98	0x62	b
3	0x03	ETX	35	0x23	#	67	0x43	C	99	0x63	c
4	0x04	EOT	36	0x24	$	68	0x44	D	100	0x64	d
5	0x05	ENQ	37	0x25	%	69	0x45	E	101	0x65	e
6	0x06	ACK	38	0x26	&	70	0x46	F	102	0x66	f
7	0x07	BEL	39	0x27	'	71	0x47	G	103	0x67	g
8	0x08	BS	40	0x28	(	72	0x48	H	104	0x68	h
9	0x09	HT	41	0x29	)	73	0x49	I	105	0x69	i
10	0x0A	LF	42	0x2A	*	74	0x4A	J	106	0x6A	j
11	0x0B	VT	43	0x2B	+	75	0x4B	K	107	0x6B	k
12	0x0C	FF	44	0x2C	,	76	0x4C	L	108	0x6C	l
13	0x0D	CR	45	0x2D	-	77	0x4D	M	109	0x6D	m
14	0x0E	SO	46	0x2E	.	78	0x4E	N	110	0x6E	n
15	0x0F	SI	47	0x2F	/	79	0x4F	O	111	0x6F	o
16	0x10	DLE	48	0x30	0	80	0x50	P	112	0x70	p
17	0x11	DC1	49	0x31	1	81	0x51	Q	113	0x71	q
18	0x12	DC2	50	0x32	2	82	0x52	R	114	0x72	r
19	0x13	DC3	51	0x33	3	83	0x53	S	115	0x73	s
20	0x14	DC4	52	0x34	4	84	0x54	T	116	0x74	t
21	0x15	NAK	53	0x35	5	85	0x55	U	117	0x75	u
22	0x16	SYN	54	0x36	6	86	0x56	V	118	0x76	v
23	0x17	ETB	55	0x37	7	87	0x57	W	119	0x77	w
24	0x18	CAN	56	0x38	8	88	0x58	X	120	0x78	x
25	0x19	EM	57	0x39	9	89	0x59	Y	121	0x79	y
26	0x1A	SUB	58	0x3A	:	90	0x5A	Z	122	0x7A	z
27	0x1B	ESC	59	0x3B	;	91	0x5B	[	123	0x7B	{
28	0x1C	FS	60	0x3C	<	92	0x5C	\	124	0x7C	\|
29	0x1D	GS	61	0x3D	=	93	0x5D	]	125	0x7D	}
30	0x1E	RS	62	0x3E	>	94	0x5E	^	126	0x7E	~
31	0x1F	US	63	0x3F	?	95	0x5F	_	127	0x7F	DEL

ASCII Table

ASCII Table

Frequently asked questions

How do I read a hex code like 0x72 as an ASCII character?

How many characters does ASCII have?

What is the difference between ASCII and UTF-8?