Binary Alphabet Chart

Q: What is the binary code for A?

Capital A is 01000001, which is 65 in decimal. Lowercase a is 01100001, which is 97.

Every letter of the alphabet in 8-bit binary, uppercase and lowercase, plus digits and symbols. Search for a letter or a byte, or print the page for a paper copy.

Updated November 1, 2026

Uppercase letters A to Z

Capital letters are ASCII codes 65 to 90. Every one starts with 010.

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Uppercase letters A to Z
Character	Binary	Decimal	Hex
A	01000001	65	41
B	01000010	66	42
C	01000011	67	43
D	01000100	68	44
E	01000101	69	45
F	01000110	70	46
G	01000111	71	47
H	01001000	72	48
I	01001001	73	49
J	01001010	74	4A
K	01001011	75	4B
L	01001100	76	4C
M	01001101	77	4D
N	01001110	78	4E
O	01001111	79	4F
P	01010000	80	50
Q	01010001	81	51
R	01010010	82	52
S	01010011	83	53
T	01010100	84	54
U	01010101	85	55
V	01010110	86	56
W	01010111	87	57
X	01011000	88	58
Y	01011001	89	59
Z	01011010	90	5A

Lowercase letters a to z

Lowercase letters are codes 97 to 122 and start with 011. Each is exactly 32 more than its capital.

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Lowercase letters a to z
Character	Binary	Decimal	Hex
a	01100001	97	61
b	01100010	98	62
c	01100011	99	63
d	01100100	100	64
e	01100101	101	65
f	01100110	102	66
g	01100111	103	67
h	01101000	104	68
i	01101001	105	69
j	01101010	106	6A
k	01101011	107	6B
l	01101100	108	6C
m	01101101	109	6D
n	01101110	110	6E
o	01101111	111	6F
p	01110000	112	70
q	01110001	113	71
r	01110010	114	72
s	01110011	115	73
t	01110100	116	74
u	01110101	117	75
v	01110110	118	76
w	01110111	119	77
x	01111000	120	78
y	01111001	121	79
z	01111010	122	7A

Numbers 0 to 9

These are the digits as text characters, codes 48 to 57. The digit 5 as text is not the same byte as the number 5.

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Numbers 0 to 9
Character	Binary	Decimal	Hex
0	00110000	48	30
1	00110001	49	31
2	00110010	50	32
3	00110011	51	33
4	00110100	52	34
5	00110101	53	35
6	00110110	54	36
7	00110111	55	37
8	00111000	56	38
9	00111001	57	39

Space and punctuation

The space and the symbols on a US keyboard.

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Space and punctuation
Character	Binary	Decimal	Hex
space	00100000	32	20
!	00100001	33	21
"	00100010	34	22
#	00100011	35	23
$	00100100	36	24
%	00100101	37	25
&	00100110	38	26
'	00100111	39	27
(	00101000	40	28
)	00101001	41	29
*	00101010	42	2A
+	00101011	43	2B
,	00101100	44	2C
-	00101101	45	2D
.	00101110	46	2E
/	00101111	47	2F
:	00111010	58	3A
;	00111011	59	3B
<	00111100	60	3C
=	00111101	61	3D
>	00111110	62	3E
?	00111111	63	3F
@	01000000	64	40
[	01011011	91	5B
\	01011100	92	5C
]	01011101	93	5D
^	01011110	94	5E
_	01011111	95	5F
`	01100000	96	60
{	01111011	123	7B
\|	01111100	124	7C
}	01111101	125	7D
~	01111110	126	7E

Uppercase vs lowercase in binary

An uppercase letter and its lowercase partner differ in one bit, the third from the left. A is 01000001 and a is 01100001. Flip that bit and you switch the case, which is why older programs could change case so cheaply.

The last five bits give the position of the letter in the alphabet: 00001 for A, 00010 for B, up to 11010 for Z.

Printing the chart

Use your browser's print command (Ctrl+P, or Cmd+P on a Mac). The search box is left off the printout, and you can save the result as a PDF from the print dialog.

To spell out a whole word or name, the text to binary converter is faster than the chart. To decode a message, paste it into the binary to text converter, or let the binary translator work out the direction for you. For every code from 0 to 127, including control characters, see the ASCII table.

Frequently asked questions

What is the binary code for A?

Capital A is `01000001`, which is 65 in decimal. Lowercase a is `01100001`, which is 97.

What is the difference between uppercase and lowercase in binary?

One bit. Lowercase letters have the third bit from the left set to 1, which adds 32 to the code. So A (65) becomes a (97).