A1Z26 Cipher
Encode text to position numbers (A=1, B=2, … Z=26) and decode numbers back to letters.
Separator:
Numbers
8-5-12-12-15-/-23-15-18-12-4
A–Z reference
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
How A1Z26 works
A1Z26 is a simple substitution cipher where each letter is replaced by its position in the alphabet: A=1, B=2, … Z=26. Words are separated by a delimiter (default: slash), and individual letter numbers are separated by a configurable separator. It's commonly seen in puzzles, escape rooms, and geocaching.
Built and maintained by Meet Shah · Last updated
What this tool is used for
- Solving a puzzle whose clue is a run of numbers between one and twenty-six.
- Building a simple substitution exercise for teaching, where the mapping is obvious once seen.
- Encoding a short word as numbers for a scavenger hunt or an escape-room clue.
- Checking whether a numeric sequence is letter positions rather than character codes.
- Producing a numeric form of a word where the alphabet position matters, not the byte value.
Frequently Asked Questions
- Why does it need two different separators?
- Because the numbers would otherwise be unreadable. 1123 could be 1-1-2-3, 11-2-3 or 1-12-3, so a separator between letters is mandatory; a second one — the slash — marks word boundaries, since the letter separator has already been used up. Without both, decoding is guesswork.
- What happens to punctuation and digits?
- They are dropped. Only A–Z survive, mapped to 1–26, and a space becomes a slash — so "Hello, World!" loses its comma and exclamation mark permanently. Round-tripping recovers the letters and the word breaks, never the punctuation, so keep the original if it matters.
- How are accented letters handled?
- They are removed too. É uppercases to É rather than E, and its code point is far outside the A–Z range the encoder accepts, so it simply vanishes. Strip accents to their base letters first if you are encoding French, Spanish or German text.
- What does a question mark in the decoded output mean?
- A number outside 1–26. Decoding is deliberately strict: 27 or 0 has no letter, so it becomes ? rather than wrapping around or being skipped. Seeing them usually means the wrong separator is selected and two numbers have been read as one.
- Is A1Z26 encryption?
- No — it is an encoding with no key, so anyone who recognises the pattern reads it directly. It is popular in escape rooms, geocaching and puzzle hunts precisely because it is meant to be solvable. For a keyed alternative of similar difficulty, a Caesar or Vigenère cipher at least has a secret.
Common errors and gotchas
- Using one separator for both letters and words, after which `1 2` and `12` cannot be told apart.
- Assuming digits in the input encode. Only letters have positions, so numbers must pass through or be dropped.
- Feeding in values above 26, which have no letter and usually mean the input was character codes instead.
- Expecting accented letters to map. They have no position in a twenty-six letter alphabet and come back as a placeholder.
- Treating it as encryption. It is a direct public mapping with nothing hidden and no key at all.
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