Letters to Numbers (A1Z26) Converter
Turn letters into their places in the alphabet — A = 1, B = 2 … Z = 26 — or paste a string of numbers and read the message. Choose the separators, count from Z instead of A, or start at zero; decoding accepts dashes, spaces, commas and slashes as they come.
Letters become numbers and each space becomes the word separator. Digits and letters outside A–Z are skipped. Commas, dashes and full stops are always dropped, because they separate numbers; other punctuation is kept only if you tick the box.
Letter numbers
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
Letters in your message are highlighted.
How to Use the Letters to Numbers Converter
- 1. Choose a direction. Letters → numbers encodes your text; Numbers → letters decodes a number code.
- 2. Set the format. When encoding, pick what goes between letters (a dash, a space or a comma) and between words (a slash or a double space).
- 3. Match the numbering. Tick Reverse alphabet for codes where Z = 1, or Count from zero where A = 0. The table under the tool updates to show every letter's number.
- 4. Read and copy. The result updates as you type. Digits and other characters that have no letter number are listed under the input, so you can see what was skipped.
How A1Z26 Works
A1Z26 is the simplest letter-to-number code there is: each letter is replaced by its position in the alphabet, and the name is the rule — A is 1, Z is 26. Because 10 to 26 take two digits, the numbers need separators. Without them, 1-2 (AB) and 12 (L) would look the same, which is why the output puts a dash or a space between letters and a slash between words.
| A | B | C | D | E | F | G | H | I | J | K | L | M |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 |
| N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 |
Worked example
Hello World encodes to 8-5-12-12-15 / 23-15-18-12-4: H is the 8th letter, E the 5th, L the 12th and O the 15th, and the slash marks the space. With spaces between letters, the words are told apart by a double space instead: 8 5 12 12 15, a wider gap, then 23 15 18 12 4. Decoding reverses either layout, reading each run of digits as one number.
Variants you will meet in puzzles
- Reverse alphabet (Z = 1). Counting from the other end makes A = 26 and Z = 1, so HELLO becomes 19-22-15-15-12. That is the same as running the text through the Atbash cipher first and then numbering it.
- Zero-based (A = 0). Programmers and cipher textbooks often count from zero, which keeps the arithmetic of shift ciphers tidy: HELLO becomes 7-4-11-11-14. The affine cipher numbers letters this way.
- Stacked with another cipher. Setters often shift the letters with a Caesar cipher first, so the decoded numbers spell nonsense until the shift is undone as well.
What Happens to Spaces, Digits and Punctuation
Encoding. Letters become numbers, and each run of spaces becomes the word separator; line breaks are kept. Digits are skipped, because a 7 in the output would read back as G, and so are letters outside A–Z — except accented letters, which count as their plain letter (é is 5). Commas, dashes and full stops are always dropped, since they separate the numbers. Other marks, such as ! ? and the apostrophe, are kept as tokens of their own only when Keep punctuation is ticked.
Decoding. Every run of digits is one number. A slash or two spaces start a new word and a line break starts a new line; dashes, commas, full stops and single spaces just separate numbers; any other punctuation is copied through. A number with no letter — 27, or 0 when counting from 1 — appears as a question mark and is listed, which usually points to a typo.
Code, Not Cipher
Strictly, A1Z26 is a code rather than a cipher: there is no key, so anyone who recognises it can read it, and a message made only of numbers from 1 to 26 is a giveaway. That is exactly why it is popular in puzzle hunts, escape rooms, geocache clues and activity books, where the fun is spotting the system. Writing numbers with letters is much older — Greek and Hebrew both used their alphabets as numerals — but those systems counted 1 to 9, then 10, 20 … 90, then hundreds, rather than numbering the letters in order as A1Z26 does.
Frequently Asked Questions
- What is the A1Z26 cipher?
- A1Z26 replaces each letter with its position in the alphabet: A = 1, B = 2, and so on up to Z = 26. Letters are separated by dashes or spaces so that one- and two-digit numbers can be told apart, and words by a slash or a wider gap.
- How do I convert numbers to letters?
- Switch to Numbers → letters and paste the code. Each number from 1 to 26 becomes the letter in that position — 8 is H, 9 is I — and a slash or double space becomes a space between words. A number out of range shows as a question mark, so typos stand out.
- What number is each letter of the alphabet?
- 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. The table under the tool shows the same list and updates when you reverse the alphabet or count from zero.
- Can it decode numbers written without separators?
- No, and no tool can do it reliably, because a run like 1225 could be ABBE, ABY, AVE, LBE or LY. Each run of digits is read as one number, so 1225 shows up as out of range. Add separators where the letters break, or try the possible splits by hand.
- What is the reverse A1Z26 code?
- It counts from the other end, so Z = 1 and A = 26; tick Reverse alphabet to use it. It gives the same numbers as enciphering the text with Atbash and then applying ordinary A1Z26.
- Can A1Z26 keep a message secret?
- No. It has no key, and a page of numbers between 1 and 26 is recognised at a glance. It is ideal for games and classroom puzzles, and it can be one layer of a harder puzzle, but it offers no protection on its own.