Character encodings

ASCII

Char	Name	Hex	Dec	Oct	Binary	Percent	Caret	Escape
␀	Null [NUL]	00	000	000	00000000	%00	^@	\0
␁	Start of heading [SOH]	01	001	001	00000001	%01	^A
␂	Start of text [STX]	02	002	002	00000010	%02	^B
␃	End of text [ETX]	03	003	003	00000011	%03	^C
␄	End of transmission [EOT]	04	004	004	00000100	%04	^D
␅	Enquiry [ENQ]	05	005	005	00000101	%05	^E
␆	Acknowledge [ACK]	06	006	006	00000110	%06	^F
␇	Bell [BEL]	07	007	007	00000111	%07	^G	\a
␈	Backspace [BS]	08	008	010	00001000	%08	^H	\n
␉	Horizontal tabulation [HT]	09	009	011	00001001	%09	^I	\t
␊	Line feed [LF]	0A	010	012	00001010	%0A	^J	\n
␋	Vertical tabulation [VT]	0B	011	013	00001011	%0B	^K	\v
␌	Form feed [FF]	0C	012	014	00001100	%0C	^L	\f
␍	Carriage return [CR]	0D	013	015	00001101	%0D	^M	\r
␎	Shift out [SS]	0E	014	016	00001110	%0E	^N
␏	Shift in [SI]	0F	015	017	00001111	%0F	^O
␐	Data link escape [DLE]	10	016	020	00010000	%10	^P
␑	Device control 1 [DC1]	11	017	021	00010001	%11	^Q
␒	Device control 2 [DC2]	12	018	022	00010010	%12	^R
␓	Device control 3 [DC3]	13	019	023	00010011	%13	^S
␔	Device control 4 [DC4]	14	020	024	00010100	%14	^T
␕	Negative acknowledge [NAK]	15	021	025	00010101	%15	^U
␖	Synchronous idle [SYN]	16	022	026	00010110	%16	^V
␗	End of transmission block [ETB]	17	023	027	00010111	%17	^W
␘	Cancel [CAN]	18	024	030	00011000	%18	^X
␙	End of medium [EM]	19	025	031	00011001	%19	^Y
␚	Substitute [SUB]	1A	026	032	00011010	%1A	^Z
␛	Escape [ESC]	1B	027	033	00011011	%1B	^[	\e
␜	File separator [FS]	1C	028	034	00011100	%1C	^\
␝	Group separator [GS]	1D	029	035	00011101	%1D	^]
␞	Record separator [RS]	1E	030	036	00011110	%1E	^^
␟	Unit separator [US]	1F	031	037	00011111	%1F	^_
␣	Space	20	032	040	00100000	%20
!	Exclamation point	21	033	041	00100001	%21
"	Quotation mark	22	034	042	00100010	%22		\"
#	Number sign	23	035	043	00100011	%23
$	Dollar sign	24	036	044	00100100	%24
%	Percent sign	25	037	045	00100101	%25
&	Ampersand	26	038	046	00100110	%26
'	Apostrophe	27	039	047	00100111	%27		\'
(	Left parenthesis	28	040	050	00101000	%28
)	Right parenthesis	29	041	051	00101001	%29
*	Asterisk	2A	042	052	00101010	%2A
+	Plus sign	2B	043	053	00101011	%2B
,	Comma	2C	044	054	00101100	%2C
-	Hyphen-minus	2D	045	055	00101101	%2D
.	Period	2E	046	056	00101110	%2E
/	Slash	2F	047	057	00101111	%2F
0	Digit zero	30	048	060	00110000
1	Digit one	31	049	061	00110001
2	Digit two	32	050	062	00110010
3	Digit three	33	051	063	00110011
4	Digit four	34	052	064	00110100
5	Digit five	35	053	065	00110101
6	Digit six	36	054	066	00110110
7	Digit seven	37	055	067	00110111
8	Digit eight	38	056	070	00111000
9	Digit nine	39	057	071	00111001
:	Colon	3A	058	072	00111010	%3A
;	Semicolon	3B	059	073	00111011	%3B
<	Less-than sign	3C	060	074	00111100	%3C
=	Equals sign	3D	061	075	00111101	%3D
>	Greater-than sign	3E	062	076	00111110	%3E
?	Question mark	3F	063	077	00111111	%3F		\?
@	Commercial at	40	064	100	01000000	%40
A	Latin capital letter A	41	065	1081	01000001
B	Latin capital letter B	42	066	102	01000010
C	Latin capital letter C	43	067	103	01000011
D	Latin capital letter D	44	068	104	01000100
E	Latin capital letter E	45	069	105	01000101
F	Latin capital letter F	46	070	106	01000110
G	Latin capital letter G	47	071	107	01000111
H	Latin capital letter H	48	072	110	01001000
I	Latin capital letter I	49	073	111	01001001
J	Latin capital letter J	4A	074	112	01001010
K	Latin capital letter K	4B	075	113	01001011
L	Latin capital letter L	4C	076	114	01001100
M	Latin capital letter M	4D	077	115	01001101
N	Latin capital letter N	4E	078	116	01001110
O	Latin capital letter O	4F	079	117	01001111
P	Latin capital letter P	50	080	120	01010000
Q	Latin capital letter Q	51	081	121	01010001
R	Latin capital letter R	52	082	122	01010010
S	Latin capital letter S	53	083	123	01010011
T	Latin capital letter T	54	084	124	01010100
U	Latin capital letter U	55	085	125	01010101
V	Latin capital letter V	56	086	126	01010110
W	Latin capital letter W	57	087	127	01010111
X	Latin capital letter X	58	088	130	01011000
Y	Latin capital letter Y	59	089	131	01011001
Z	Latin capital letter Z	5A	090	132	01011010
[	Left square bracket	5B	091	133	01011011	%5B
\	Backslash	5C	092	134	01011100	%5C		\\
]	Right square bracket	5D	093	135	01011101	%5D
^	Circumflex accent	5E	094	136	01011110	%5E
_	Underscore	5F	095	137	01011111	%5F
`	Grave accent	60	096	140	01100000	%60
a	Latin small letter a	61	097	141	01100001
b	Latin small letter b	62	098	142	01100010
c	Latin small letter c	63	099	143	01100011
d	Latin small letter d	64	100	144	01100100
e	Latin small letter e	65	101	145	01100101
f	Latin small letter f	66	102	146	01100110
g	Latin small letter g	67	103	147	01100111
h	Latin small letter h	68	104	150	01101000
i	Latin small letter i	69	105	151	01101001
j	Latin small letter j	6A	106	152	01101010
k	Latin small letter k	6B	107	153	01101011
l	Latin small letter l	6C	108	154	01101100
m	Latin small letter m	6D	109	155	01101101
n	Latin small letter n	6E	110	156	01101110
o	Latin small letter o	6F	111	157	01101111
p	Latin small letter p	70	112	160	01110000
q	Latin small letter q	71	113	161	01110001
r	Latin small letter r	72	114	162	01110010
s	Latin small letter s	73	115	163	01110011
t	Latin small letter t	74	116	164	01110100
u	Latin small letter u	75	117	165	01110101
v	Latin small letter v	76	118	166	01110110
w	Latin small letter w	77	119	167	01110111
x	Latin small letter x	78	120	170	01111000
y	Latin small letter y	79	121	171	01111001
z	Latin small letter z	7A	122	172	01111010
{	Left curly brace	7B	123	173	01111011	%7B
|	Vertical line	7C	124	174	01111100	%7C
}	Right curly brace	7D	125	175	01111101	%7D
~	Tilde	7E	126	176	01111110	%7E
␡	Delete [DEL]	7F	127	177	01111111	%7F	^?

Percent encoding

Used to encode reserved characters in URIs and URLs. Those with a blue background are reserved and must be encoded, those with a red background are not technically allowable in URIs, but can be included when encoded, those with a white background may be encoded optionally, but do not have to be.

For ASCII characters, the encoding is simply the value in hex prefaced by a percent sign. For Unicode characters, it's a more complicated system of multiple encoded values.

Any reserved symbols in the file name of a files downloaded from a web site may be encoded with these.

Caret notation

Used in older systems both as a way to display the non-printable character values and enter the characters as input since few have a keyboard equivalent. The most common way to enter these values is to hold the Control key on a keyboard, then press the corresponding character. For example, Control+H will have the same effect as pressing the backspace key in many terminals.

Escape notion

Used in C-like languages to "escape" normal interpretation. This allows a programmer to tell the compiler not to interpret the following at face value, but instead convert it to the corresponding ASCII value.