ASCII Table

ASCII is an acronym for American Standard Code for Information Interchange. Yeah, that doesn’t really tell us much about what an ASCII code is, or why we should care about an ASCII table.

For that, we need to remember that computers only understand numbers. And only binary numbers at that. When you press the A key on your keyboard, we need a way for your computer to know what key was pressed. And since it doesn’t understand letters, we have to use numbers.

If you scroll down on the ASCII table below and find the capital letter A you’ll see that it has an ASCII value of 65, which is 0100 0001 in binary. That number is sent from your keyboard to your computer and the computer interprets it as an A. The same thing happens in data files. It’s the number that’s ultimately needed, not the character.

And if you’d like a little more information on ASCII, head on over to Wikipedia.

ASCII Table

Here you’ll find a list of the first 127 ASCII codes that your computer knows how to work with. We’re no longer limited to just 127, but when people talk about ASCII tables, this is usually the list they’re talking about.

You can probably skip over the first 31. They’re system codes that tell the computer how to do things, but don’t typically show up on screen. There are a few interesting ones in there though. For example, pressing the enter key on your keyboard sends the code 13.

Visible characters start at 32 with space. Okay, so I guess space really isn’t a visible character.

If you’re using this ASCII table for an intro to programming course you probably really only have to memorize 3 or 4 different numbers. The first one is space, which is code 32. Then you’ll want to remember lower case a (97), capital A (65) and zero (48). From there you can figure out the other letters and numbers. Since the letters and number are sequential you can work out the rest. For example, a lower case d is 100 – 3 characters after lower case a.

Character Decimal Binary Octal Hex
(null) 0 0 0 0
(start of heading) 1 1 1 1
(start of text) 2 10 2 2
(end of text) 3 11 3 3
(end of transmission) 4 100 4 4
(enquiry) 5 101 5 5
(acknowledge) 6 110 6 6
(bell) 7 111 7 7
(backspace) 8 1000 10 8
(horizontal tab) 9 1001 11 9
(new line) 10 1010 12 A
(vertical tab) 11 1011 13 B
(new page) 12 1100 14 C
(carriage return) 13 1101 15 D
(shift out) 14 1110 16 E
(shift in) 15 1111 17 F
(data link escape) 16 10000 20 10
(device control 1) 17 10001 21 11
(device control 2) 18 10010 22 12
(device control 3) 19 10011 23 13
(device control 4) 20 10100 24 14
(negative acknowledge) 21 10101 25 15
(synchronous idle) 22 10110 26 16
(end of trans block) 23 10111 27 17
(cancel) 24 11000 30 18
(end of medium) 25 11001 31 19
(substitute) 26 11010 32 1A
(escape) 27 11011 33 1B
(file separator) 28 11100 34 1C
(group separator) 29 11101 35 1D
(record separator) 30 11110 36 1E
(unit separator) 31 11111 37 1F
(SPACE) 32 100000 40 20
! 33 100001 41 21
" 34 100010 42 22
# 35 100011 43 23
$ 36 100100 44 24
% 37 100101 45 25
& 38 100110 46 26
39 100111 47 27
( 40 101000 50 28
) 41 101001 51 29
* 42 101010 52 2A
+ 43 101011 53 2B
, 44 101100 54 2C
45 101101 55 2D
. 46 101110 56 2E
/ 47 101111 57 2F
0 48 110000 60 30
1 49 110001 61 31
2 50 110010 62 32
3 51 110011 63 33
4 52 110100 64 34
5 53 110101 65 35
6 54 110110 66 36
7 55 110111 67 37
8 56 111000 70 38
9 57 111001 71 39
: 58 111010 72 3A
; 59 111011 73 3B
< 60 111100 74 3C
= 61 111101 75 3D
> 62 111110 76 3E
? 63 111111 77 3F
` 64 1000000 100 40
A 65 1000001 101 41
B 66 1000010 102 42
C 67 1000011 103 43
D 68 1000100 104 44
E 69 1000101 105 45
F 70 1000110 106 46
G 71 1000111 107 47
H 72 1001000 110 48
I 73 1001001 111 49
J 74 1001010 112 4A
K 75 1001011 113 4B
L 76 1001100 114 4C
M 77 1001101 115 4D
N 78 1001110 116 4E
O 79 1001111 117 4F
P 80 1010000 120 50
Q 81 1010001 121 51
R 82 1010010 122 52
S 83 1010011 123 53
T 84 1010100 124 54
U 85 1010101 125 55
V 86 1010110 126 56
W 87 1010111 127 57
X 88 1011000 130 58
Y 89 1011001 131 59
Z 90 1011010 132 5A
[ 91 1011011 133 5B
\ 92 1011100 134 5C
] 93 1011101 135 5D
^ 94 1011110 136 5E
_ 95 1011111 137 5F
` 96 1100000 140 60
a 97 1100001 141 61
b 98 1100010 142 62
c 99 1100011 143 63
d 100 1100100 144 64
e 101 1100101 145 65
f 102 1100110 146 66
g 103 1100111 147 67
h 104 1101000 150 68
i 105 1101001 151 69
j 106 1101010 152 6A
k 107 1101011 153 6B
l 108 1101100 154 6C
m 109 1101101 155 6D
n 110 1101110 156 6E
o 111 1101111 157 6F
p 112 1110000 160 70
q 113 1110001 161 71
r 114 1110010 162 72
s 115 1110011 163 73
t 116 1110100 164 74
u 117 1110101 165 75
v 118 1110110 166 76
w 119 1110111 167 77
x 120 1111000 170 78
y 121 1111001 171 79
z 122 1111010 172 7A
{ 123 1111011 173 7B
| 124 1111100 174 7C
} 125 1111101 175 7D
~ 126 1111110 176 7E
(delete) 127 1111111 177 7F
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