A1Z26 Cipher Encoder
A1Z26 is the simplest numeric cipher: A becomes 1, B becomes 2, and so on to Z equals 26. Paste plain text to get the numeric sequence, or paste numbers separated by hyphens, commas or spaces to recover the original word. Handy for puzzle hunts, escape room clues and teaching substitution ciphers.
How A1Z26 encoding and decoding works
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1
Choose encode or decode
Switch the mode depending on whether your input is letters or a number sequence.
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2
Paste the input
For encoding, type any text (case is ignored, non-letters are dropped). For decoding, paste numbers separated by your chosen character.
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3
Pick the separator
Hyphen (1-2-3), comma (1,2,3) and space (1 2 3) are the common conventions used in puzzle communities.
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4
Copy the result
Hit copy to drop the encoded sequence or decoded word into a chat, document or puzzle solution log.
The full A1Z26 mapping
| Letter | Number | Letter | Number | Letter | Number |
|---|---|---|---|---|---|
| A | 1 | J | 10 | S | 19 |
| B | 2 | K | 11 | T | 20 |
| C | 3 | L | 12 | U | 21 |
| D | 4 | M | 13 | V | 22 |
| E | 5 | N | 14 | W | 23 |
| F | 6 | O | 15 | X | 24 |
| G | 7 | P | 16 | Y | 25 |
| H | 8 | Q | 17 | Z | 26 |
| I | 9 | R | 18 |
Why A1Z26 appears in puzzle hunts
It is a single-step, reversible cipher with no key, so any solver who recognises the pattern can decode instantly. Puzzle setters use it as the first layer of a multi-step puzzle, for example A1Z26 plus a Caesar shift, or A1Z26 where the numbers form a coordinate when read as a phone keypad layout.
Spotting A1Z26 in the wild
- Sequences of integers where every value is between 1 and 26.
- Groups of numbers separated consistently by hyphens, commas or dots.
- The number groups roughly match the expected plaintext length, with one or two digits per letter plus separators.
A1Z26 is not encryption
It is a cipher, not a keyed encryption method. Anyone who recognises the mapping can decode it instantly. Never use A1Z26 for anything that needs to stay secret: it offers zero protection.
Frequently Asked Questions
A hyphen (1-2-3) is the most common puzzle convention because it makes multi-digit numbers unambiguous without needing spaces. Use commas for CSV-style input.
The tool usually inserts a double separator or a slash between words (for example, 8-9 / 20-8-5-18-5 for “HI THERE”). Commas and punctuation are dropped because A1Z26 only maps the 26 letters.
A1Z26 is defined only for the 26 unaccented letters of the Latin alphabet. Accents are typically stripped (é becomes e) and characters outside A-Z are skipped.
No. A Caesar cipher shifts letters to other letters (A to D, for example). A1Z26 converts letters to numbers. The two are often chained together as a two-step puzzle.
Check your separator. Without one, 1123 could mean A-A-B-C, A-L-C, K-M or 1-1-23, which all decode differently. A consistent separator is required for unambiguous decoding.
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