Letters to numbers converter (A1Z26 cipher)

How the letters to numbers converter works

Type or paste your text and each letter turns into its position in the alphabet: A is 1, B is 2, and so on up to Z at 26. This is the A1Z26 cipher, one of the simplest codes there is. With the default settings, “Hello world” comes out as “8 5 12 12 15 / 23 15 18 12 4”.

Capital and small letters give the same number, and accented letters count as their base letter, so “é” is 5, the same as “e”. Digits, punctuation, and other characters pass through unchanged, so a date or a question mark stays where it was. Each word is separated from the next by “ / ”, which keeps the code easy to read when you decode it later.

Numbers to letters: decode an A1Z26 message

Switch the direction to “Numbers → letters” and paste the code. Separate the numbers with the separator you pick in the options, a space, a dash, or a comma, and mark each new word with “/” or a line break. “8 9 / 20 8 5 18 5” decodes to “hi there”.

Choose uppercase or lowercase for the letters you get back. If a number has no letter, the converter shows an error that names it, so with the English alphabet “27” gets flagged instead of guessed. That usually means a typo, a code that starts at A=0, or a message written with the Spanish alphabet.

English or Spanish alphabet, A=1 or A=0

The English alphabet has 26 letters. The Spanish one has 27, because Ñ sits right after N as letter 15, which moves every letter after it up by one: O is 16 and Z is 27. This page starts on the English alphabet. If a puzzle comes from a Spanish book or game, switch to Spanish, or every letter from O onward will be off by one.

Some puzzles count from zero, so A is 0, B is 1, and Z is 25. Pick “A=0” when the numbers you have include a 0, or when the puzzle says so. Here is “sol” in three settings:

• English, starting at A=1: 19 15 12
• English, starting at A=0: 18 14 11
• Spanish, starting at A=1: 20 16 12

Letter sums, puzzles, and secret codes

Under the result, the sum adds up the value of every letter. “Hello world” adds up to 124. Word value games and some puzzle hunts ask for exactly that total, so you can test several answers quickly without adding by hand.

The A1Z26 code turns up in escape rooms, geocaching caches, and puzzle hunts, and it makes a good first cipher for kids writing secret notes or for a classroom activity on codes. Everything runs in your browser and your text is never uploaded. The box takes up to 500,000 characters, and “Copy result” and “Download TXT” save what you get.