Letter to Number Cipher (A1Z26)

Convert letters to numbers (A=1 to Z=26) and numbers back to letters. Choose dashes, spaces or commas as separators, or switch to A=0 numbering.

The A1Z26 cipher replaces each letter with its position in the alphabet: A is 1, B is 2 and so on up to Z, which is 26. HELLO WORLD becomes 8-5-12-12-15 23-15-18-12-4, with dashes between letters and a space between words. To decode, paste the numbers: the tool accepts dashes, commas, periods or spaces between letters, and treats slashes, double spaces or a space between dash-separated groups as word breaks. Numbers outside 1 to 26 are marked with a question mark so typos stand out. Some puzzles count from zero (A is 0, Z is 25); switch on A=0 for those. Numbers run together without separators can't be read with certainty: 1225 could be ABBE, AVE, ABY, LBE or LY, so the tool flags them.

Letter to number chart

A
1
B
2
C
3
D
4
E
5
F
6
G
7
H
8
I
9
J
10
K
11
L
12
M
13
N
14
O
15
P
16
Q
17
R
18
S
19
T
20
U
21
V
22
W
23
X
24
Y
25
Z
26

Common use cases

  • Decode number clues such as 8-5-12-16 in escape rooms and puzzle hunts
  • Turn a word into a lock combination or a number puzzle
  • Make letter-number worksheets for students
  • Check whether a list of numbers is A1Z26 before trying other codes

How to use

  1. Choose Letters to numbers or Numbers to letters.
  2. Type or paste your text or numbers.
  3. When encoding, pick the separator between letters and between words.
  4. Switch on A=0 if the puzzle counts from zero, then copy the result.

FAQ

What is the A1Z26 cipher?

A simple substitution that replaces each letter with its number in the alphabet: A is 1 and Z is 26, hence the name. It has no key, so it's a puzzle step rather than real encryption.

Should I use A=1 or A=0?

A=1 is the usual convention in puzzles and escape rooms. A=0 appears in programming and in ciphers built on modular arithmetic, such as the Caesar and Vigenère ciphers, where A stands for a shift of 0.

How do I mark the spaces between words?

Separate letters with dashes and words with a space (8-9 20-8-5-18-5), or letters with spaces and words with a slash (8 9 / 20 8 5 18 5). The tool decodes both styles.

What happens to digits and punctuation in my text?

Digits are dropped when encoding, because they'd be confused with the letter numbers. Punctuation is dropped too unless you tick Keep punctuation.

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