Reference Chart

Binary Alphabet: Every Letter A–Z in Binary Code

Complete binary code chart for all 52 English letters — uppercase and lowercase — with decimal and hex values. Plus the pattern behind it, common words in binary, and how to write your name in binary code.

What Is the Binary Alphabet?

The binary alphabet is the set of 8-bit codes that represent each English letter inside a computer. Every character you type, read, or transmit digitally — from a Slack message to a line of code — is stored as a sequence of 0s and 1s. The mapping between letters and binary values is defined by ASCII (American Standard Code for Information Interchange), the encoding standard used since 1963 and still the foundation of modern text encoding like UTF-8.

Uppercase A starts at decimal 65 (binary 01000001). Lowercase a starts at decimal 97 (binary 01100001). Both sets run consecutively from there: B is 66, C is 67, all the way through Z at 90 — and b is 98 through z at 122. This makes the binary alphabet one of the most orderly structures in computing.

Uppercase Letters A–Z in Binary

8-bit ASCII binary codes for all 26 uppercase English letters, with decimal and hexadecimal equivalents.

Letter Binary (8-bit) Decimal Hex

Lowercase Letters a–z in Binary

8-bit ASCII binary codes for all 26 lowercase English letters. Each is exactly 32 higher than its uppercase counterpart.

Letter Binary (8-bit) Decimal Hex

The Pattern Behind the Binary Alphabet

You don't need to memorize 52 codes. Once you understand the structure, you can derive any letter's binary from two rules.

01

Letters are consecutive

A=65, B=66, C=67 … Z=90. Each letter's decimal code is exactly one more than the previous. In binary, the last 5 bits count the letter's position in the alphabet: A=00001, B=00010, C=00011, and so on up to Z=11010 (26). Know where the sequence starts and you can count to any letter.

1bit

Case is a single bit

Uppercase and lowercase versions of the same letter differ by exactly 32 — which is 00100000 in binary, a single bit flip at position 6 (counting from the right). Flip that bit in A (01000001) and you get a (01100001). This was an intentional ASCII design decision that makes case conversion computationally trivial.

Visual: The Single-Bit Case Flip

Uppercase A (decimal 65)
01000001
Lowercase a (decimal 97)
01100001

The highlighted bit (position 6) is the only difference. 0 = uppercase, 1 = lowercase. This holds for every letter A–Z.

Digits 0–9 in Binary

For completeness, here are the ASCII binary codes for the ten decimal digits. These start at decimal 48.

Digit Binary (8-bit) Decimal Hex

Common Words and Phrases in Binary

Pre-converted for quick reference. Each space between words is 00100000 (decimal 32).

"hello"
01101000 01100101 01101100 01101100 01101111
"love"
01101100 01101111 01110110 01100101
"Hello World"
01001000 01100101 01101100 01101100 01101111 00100000 01010111 01101111 01110010 01101100 01100100
"yes"
01111001 01100101 01110011
"no"
01101110 01101111
"binary"
01100010 01101001 01101110 01100001 01110010 01111001
"thank you"
01110100 01101000 01100001 01101110 01101011 00100000 01111001 01101111 01110101
"I love you"
01001001 00100000 01101100 01101111 01110110 01100101 00100000 01111001 01101111 01110101

Need a different word or sentence? Use our binary converter to translate any text instantly.

✍️ How to Write Your Name in Binary Code

Converting your name to binary is a simple lookup exercise. Here's a step-by-step walkthrough using the name "Sam" as an example.

  1. 1

    Find each letter in the chart above

    S is uppercase → look in the A–Z table: 01010011 (decimal 83). a is lowercase → a–z table: 01100001 (decimal 97). m is lowercase: 01101101 (decimal 109).

  2. 2

    Place the codes in order with spaces between bytes

    S a m 01010011 01100001 01101101
  3. 3

    Verify by decoding it back

    Paste 01010011 01100001 01101101 into our Binary to Text Converter — it should output "Sam". If it doesn't, check each byte against the chart.

Convert your name to binary →

Related Tools You'll Find Useful

The binary alphabet is part of the ASCII standard. These tools let you convert between every common encoding format — all free, all in your browser.

Binary to Text Converter
Paste binary code and get text instantly — or go the other direction.
Full ASCII Table
All 128 characters — letters, digits, punctuation, and control codes.
Binary to Decimal
Step-by-step power-of-2 breakdown for understanding how binary values work.

Frequently Asked Questions

What is A in binary?
Uppercase A is 01000001 in 8-bit binary (decimal 65, hex 0x41). Lowercase a is 01100001 (decimal 97, hex 0x61). They differ by exactly one bit — the third bit from the left — which represents the value 32.
How do I write my name in binary?
Look up each letter in the binary alphabet chart, copy its 8-bit code, and place the codes side by side in order with spaces between each byte. For example, "Sam" is 01010011 01100001 01101101. For longer names, use our text to binary converter to do it instantly.
Why do uppercase and lowercase letters have different binary codes?
ASCII was designed so that uppercase and lowercase versions of the same letter differ by exactly 32 (binary 00100000). This means flipping one bit — the sixth bit — switches between cases. It's an intentional design choice that makes case conversion extremely fast for computers.
What is "hello" in binary?
The word "hello" in binary is: 01101000 01100101 01101100 01101100 01101111. Each group of 8 bits represents one letter: h=01101000, e=01100101, l=01101100, l=01101100, o=01101111.
How many bits does each letter use?
In ASCII and UTF-8 encoding, each English letter uses exactly 8 bits (1 byte). There are 26 letters × 2 cases = 52 unique letter codes, all fitting within the range of a single byte (0–255). Non-English characters and emojis use 2–4 bytes in UTF-8.
What is the pattern behind the binary alphabet?
The binary codes for letters follow a consecutive pattern. A=65, B=66, C=67, all the way to Z=90. Lowercase starts at a=97. The last 5 bits of each code represent the letter's position in the alphabet (A=00001, B=00010, etc.), while the leading bits indicate uppercase (010) or lowercase (011).