Binary alphabet

Every letter of the English alphabet in 8-bit binary, upper and lower case, and the simple pattern hidden in the codes.

Your name in binary

A01000001d01100100a01100001

Binary letters A–Z
Letter	Uppercase	Dec	Letter	Lowercase	Dec
A	01000001	65	a	01100001	97
B	01000010	66	b	01100010	98
C	01000011	67	c	01100011	99
D	01000100	68	d	01100100	100
E	01000101	69	e	01100101	101
F	01000110	70	f	01100110	102
G	01000111	71	g	01100111	103
H	01001000	72	h	01101000	104
I	01001001	73	i	01101001	105
J	01001010	74	j	01101010	106
K	01001011	75	k	01101011	107
L	01001100	76	l	01101100	108
M	01001101	77	m	01101101	109
N	01001110	78	n	01101110	110
O	01001111	79	o	01101111	111
P	01010000	80	p	01110000	112
Q	01010001	81	q	01110001	113
R	01010010	82	r	01110010	114
S	01010011	83	s	01110011	115
T	01010100	84	t	01110100	116
U	01010101	85	u	01110101	117
V	01010110	86	v	01110110	118
W	01010111	87	w	01110111	119
X	01011000	88	x	01111000	120
Y	01011001	89	y	01111001	121
Z	01011010	90	z	01111010	122

The pattern: a prefix plus a count

Look at the shaded prefixes. Every capital starts 010, every lowercase letter starts 011. The remaining five bits simply count through the alphabet in binary: A is 1 (00001), B is 2, and Z is 26 (11010). The only difference between “A” and “a” is the third bit, worth 32.

Flip that bit yourself: set the switches to 65 below (64 + 1), then turn on the 32 switch and you're at 97, lowercase a.

64 + 1 = 65 · hex 41 · octal 101 · ASCII A

Digits follow a similar rule: “0” to “9” are 0011 followed by the digit in 4 bits. Punctuation, symbols and control codes are in the full ASCII table. To decode a message written in binary letters, paste it into the binary translator.

Questions people ask

What is the binary alphabet?

It is the list of letters with their 8-bit ASCII codes. Uppercase A–Z run from 01000001 (65) to 01011010 (90); lowercase a–z from 01100001 (97) to 01111010 (122).

What is A in binary?

Capital A is 01000001. Lowercase a is 01100001.

How can I remember the binary letters?

Every uppercase letter starts 010 and every lowercase letter starts 011. The last five bits are the letter’s position in the alphabet: A = 00001, B = 00010, … Z = 11010. So you only need to count in 5-bit binary.

How do I write my name in binary?

Type it in the box on this page and each letter’s byte appears below, or use the full text to binary converter.