How do I convert a character to hex by hand?

Look up its ASCII decimal code, divide by 16, and write the quotient and the remainder as hex digits, with 10 to 15 written as A to F. For k: 107 ÷ 16 = 6 remainder 11, so k = 6B.

What is “Hello” in hex?

48 65 6C 6C 6F. In lowercase, “hello” is 68 65 6C 6C 6F, and “Hello World” is 48 65 6C 6C 6F 20 57 6F 72 6C 64.

Do uppercase and lowercase letters have different hex codes?

Yes. A to Z are 41 to 5A and a to z are 61 to 7A. Each lowercase letter is exactly 20 hex (32 decimal) above its capital: M = 4D, m = 6D.

What is the hex code for a space, and for the digits 0 to 9?

Space is 20 (decimal 32). The digits 0 to 9 are 30 to 39, so the second hex digit is the number itself: 7 is 37.

What happens with characters that are not ASCII?

Anything above 7F is outside ASCII, so the result depends on the Character encoding menu. On Unicode code points, the default, é is E9 and € is 20AC. UTF-8 bytes give é as C3 A9, € as E2 82 AC and 😀 as F0 9F 98 80. UTF-16 LE and BE, Windows-1252 and ISO-8859-1 are there too; Windows-1252 writes € as 80, and ISO-8859-1, which has no €, writes 3F.

How do I convert hex back to ASCII?

Switch to Hex → ASCII and paste the hex. Pairs can run together or be separated by spaces, commas or hyphens, and a 0x in front of a pair is ignored: 48 65 6C 6C 6F, 48656C6C6F and 0x48,0x65,0x6C,0x6C,0x6F all decode to Hello.

ASCII to Hex Converter

Convert ASCII text or single characters to hex and back. Hello = 48 65 6C 6C 6F. Includes a printable ASCII to hex table. How it works

Character encoding

ASCII Text

Format

Hex output

11 characters as hex

Hex Output

48 65 6C 6C 6F 20 57 6F 72 6C 64

About the ASCII to Hex Converter

In ASCII, “Hello” is 48 65 6C 6C 6F in hex: H = 48, e = 65, l = 6C, o = 6F. Every printable ASCII character has a two-digit hex code, from 20 (space) to 7E (~).

ASCII to hex table (codes 32 to 127)

Char (32–63)	Dec (32–63)	Hex (20–3F)	Char (64–95)	Dec (64–95)	Hex (40–5F)	Char (96–127)	Dec (96–127)	Hex (60–7F)
space	32	20	@	64	40	`	96	60
!	33	21	A	65	41	a	97	61
"	34	22	B	66	42	b	98	62
#	35	23	C	67	43	c	99	63
$	36	24	D	68	44	d	100	64
%	37	25	E	69	45	e	101	65
&	38	26	F	70	46	f	102	66
'	39	27	G	71	47	g	103	67
(	40	28	H	72	48	h	104	68
)	41	29	I	73	49	i	105	69
*	42	2A	J	74	4A	j	106	6A
+	43	2B	K	75	4B	k	107	6B
,	44	2C	L	76	4C	l	108	6C
-	45	2D	M	77	4D	m	109	6D
.	46	2E	N	78	4E	n	110	6E
/	47	2F	O	79	4F	o	111	6F
0	48	30	P	80	50	p	112	70
1	49	31	Q	81	51	q	113	71
2	50	32	R	82	52	r	114	72
3	51	33	S	83	53	s	115	73
4	52	34	T	84	54	t	116	74
5	53	35	U	85	55	u	117	75
6	54	36	V	86	56	v	118	76
7	55	37	W	87	57	w	119	77
8	56	38	X	88	58	x	120	78
9	57	39	Y	89	59	y	121	79
:	58	3A	Z	90	5A	z	122	7A
;	59	3B	[	91	5B	{	123	7B
<	60	3C	\	92	5C	\|	124	7C
=	61	3D	]	93	5D	}	125	7D
>	62	3E	^	94	5E	~	126	7E
?	63	3F	_	95	5F	DEL (control)	127	7F

Codes 0 to 31 and 127 (DEL) are control characters with no printed symbol. The ones you meet most: tab = 09, line feed = 0A, carriage return = 0D.

“Hello” in each output format

Format	Output
Spaced, uppercase	48 65 6C 6C 6F
Spaced, lowercase	48 65 6c 6c 6f
Continuous	48656C6C6F
0x prefix	0x48 0x65 0x6C 0x6C 0x6F
Backslash-x escapes	\x48\x65\x6C\x6C\x6F
HTML entities	Hello
Array literal	[0x48, 0x65, 0x6C, 0x6C, 0x6F]
Unicode escapes	\u0048\u0065\u006C\u006C\u006F

é, € and 😀 in each character encoding

Encoding	é	€	😀
Unicode code points (default)	E9	20AC	1F600
UTF-8 bytes	C3 A9	E2 82 AC	F0 9F 98 80
UTF-16 LE bytes	E9 00	AC 20	3D D8 00 DE
UTF-16 BE bytes	00 E9	20 AC	D8 3D DE 00
Windows-1252 bytes	E9	80	3F (not in the set)
ISO-8859-1 (Latin-1) bytes	E9	3F (not in the set)	3F (not in the set)

A character a single-byte set cannot hold is written as 3F, the byte for ?, and the page counts how many were replaced.

Methodology

Each character is replaced by its character code written in base 16 and padded to two digits. For plain ASCII text that code is the ASCII value, one byte per character. With a byte encoding chosen in the Character encoding menu (UTF-8, UTF-16 LE or BE, Windows-1252 or ISO-8859-1), the text is encoded in it first and every byte is listed. Hex → ASCII reads the input two hex digits at a time as bytes and decodes them as UTF-8, or in the chosen encoding, so 48 65 6C 6C 6F gives Hello and C3 A9 gives é. Groups written as &#x…; or \u… are read as code points.

How to use this tool

Type or paste text. The hex appears as you type; the page opens with “Hello World”, which is 48 65 6C 6C 6F 20 57 6F 72 6C 64.
Pick an output format and copy the result. The Character Inspector lists the decimal and hex code of every character.
Switch to Hex → ASCII to decode. Switching direction empties the input box, so copy anything you still need first.

Frequently asked questions

How do I convert a character to hex by hand?: Look up its ASCII decimal code, divide by 16, and write the quotient and the remainder as hex digits, with 10 to 15 written as A to F. For k: 107 ÷ 16 = 6 remainder 11, so k = 6B.
What is “Hello” in hex?: 48 65 6C 6C 6F. In lowercase, “hello” is 68 65 6C 6C 6F, and “Hello World” is 48 65 6C 6C 6F 20 57 6F 72 6C 64.
Do uppercase and lowercase letters have different hex codes?: Yes. A to Z are 41 to 5A and a to z are 61 to 7A. Each lowercase letter is exactly 20 hex (32 decimal) above its capital: M = 4D, m = 6D.
What is the hex code for a space, and for the digits 0 to 9?: Space is 20 (decimal 32). The digits 0 to 9 are 30 to 39, so the second hex digit is the number itself: 7 is 37.
What happens with characters that are not ASCII?: Anything above 7F is outside ASCII, so the result depends on the Character encoding menu. On Unicode code points, the default, é is E9 and € is 20AC. UTF-8 bytes give é as C3 A9, € as E2 82 AC and 😀 as F0 9F 98 80. UTF-16 LE and BE, Windows-1252 and ISO-8859-1 are there too; Windows-1252 writes € as 80, and ISO-8859-1, which has no €, writes 3F.
How do I convert hex back to ASCII?: Switch to Hex → ASCII and paste the hex. Pairs can run together or be separated by spaces, commas or hyphens, and a 0x in front of a pair is ignored: 48 65 6C 6C 6F, 48656C6C6F and 0x48,0x65,0x6C,0x6C,0x6F all decode to Hello.

Getting bytes instead of code points

Plain ASCII gives one two-digit code per character, the same bytes a hex editor or a packet capture shows. Text with é, ñ, € or emoji is different. With the Character encoding menu on Unicode code points, the default, € is 20AC. Choose UTF-8 bytes to get what a UTF-8 file or web request holds: € is E2 82 AC and é is C3 A9. UTF-16 LE writes € as AC 20 and UTF-16 BE as 20 AC. Windows-1252 writes it as 80, while ISO-8859-1 has no euro sign, so it writes 3F (a question mark) and the page warns you. The format buttons then give the result spaced, continuous, with a 0x prefix, as an array, as HTML entities or as backslash escapes for source code.

How text becomes hex and back

Each character code is written in base 16 and padded to two digits: ~ = 126 = 7 × 16 + 14, and 14 is E, so ~ is 7E. Going from hex to text, a list of two-digit groups is read as bytes and decoded as UTF-8. If those bytes are not valid UTF-8, each byte becomes one character instead, so E9 on its own still reads as é. With a byte encoding chosen, the pairs are decoded in that encoding instead: 80 E9 is €é in Windows-1252 and 48 00 69 00 is Hi in UTF-16 LE. A group of three or more digits, an HTML entity or a backslash-u escape is read as a code point.

Fun Fact: In ASCII, A is 0x41 (binary 0100 0001) and a is 0x61 (0110 0001). Every capital and its lowercase letter differ only in the bit worth 0x20, so flipping that single bit switches the case of any ASCII letter.

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