How to Convert Letters to Numbers (A=1, B=2) Online (2026)
The A1Z26 cipher is the simplest code there is: A=1, B=2, all the way to Z=26. The Letter to Number Converter turns text into those numbers (and back) instantly, with your choice of separator and a 1-based or 0-based offset. Here’s how the cipher works, where it shows up (escape rooms, puzzle hunts, classrooms) and why it counts as encoding rather than real encryption.
What Is the A1Z26 Cipher
The A1Z26 cipher is a simple substitution cipher that maps each letter of the alphabet to its position number: A becomes 1, B becomes 2, all the way to Z which becomes 26. It is one of the oldest and simplest codes, often used in escape rooms, puzzle hunts, classroom activities, and secret messages between kids. The name “A1Z26” comes from the first and last letter mappings: A=1 and Z=26. Unlike more complex ciphers like Caesar or ROT13, A1Z26 is not really encryption since the mapping is public and predictable: it is better described as an encoding scheme. You can customize the output with different separators (space, comma, dash) and toggle between 1-based (A=1) and 0-based (A=0) offsets.
How to Use Our Letter to Number Converter
- Open the Letter to Number Converter and type or paste your text into the input field.
- Choose a separator to place between each number: space, comma, dash, or a custom separator.
- Toggle the offset preference between 1-based (A=1, B=2) and 0-based (A=0, B=1).
- Copy the resulting numeric output from the result area.
Example Letter to Number Conversions
| Input Text | Separator | Offset | Output |
|---|---|---|---|
| ABC | Space | A=1 (1-based) | 1 2 3 |
| hello | Comma | A=1 (1-based) | 8,5,12,12,15 |
| HELLO | Dash | A=1 (1-based) | 8-5-12-12-15 |
| Code | Space | A=0 (0-based) | 2 14 3 4 |
| XYZ | Custom ”:“ | A=1 (1-based) | 24:25:26 |
Common Use Cases
- Puzzles and escape rooms: hide clues as numeric codes that players must decode.
- Secret messages: kids and friends exchange encoded notes that are easy to decode with the key.
- Educational activities: teach number-letter associations and basic cryptography concepts.
- Data processing: convert alphabetical data to numeric format for analysis or algorithms.
- Creative writing: encode character names or locations as numbers for world-building.
FAQ
Does this handle non-English letters?
The converter maps standard A-Z English characters. Non-English characters like accented letters (é, ñ, ü) are either ignored or output directly based on your settings. The cipher is designed for the 26-letter English alphabet.
Is the A1Z26 cipher case-sensitive?
No. A1Z26 alphabet mapping assigns the same number to uppercase and lowercase letters: “A” and “a” are both 1, “Z” and “z” are both 26. The case of the input letter does not affect the numeric output.
What is the difference between 1-based and 0-based offset?
1-based offset follows the standard A=1, B=2, C=3 pattern where A starts at 1. 0-based offset starts at A=0, giving B=1, C=2, and so on. Use 1-based for traditional A1Z26 encoding and 0-based for programming contexts where index counting starts at zero.
Can I decode numbers back into letters?
Yes. The same Letter to Number Converter works in reverse: paste numbers separated by your chosen delimiter and the tool will convert them back into letters.
Is A1Z26 actually secure?
No, and it isn’t meant to be. The mapping is public and fixed, so anyone can decode it in seconds. It’s an encoding for puzzles and learning, not a cipher for protecting real secrets; for that you’d want genuine encryption.
Setting a puzzle clue or decoding one? The Letter to Number Converter handles A1Z26 both ways: pick your separator and offset, and it converts the moment you type.