How to decode a number message
Paste the numbers into the box and the letters appear at once, using 1 = A, 2 = B and so on up to 26 = Z. Separate the numbers for each letter with hyphens, commas, dots or spaces, and leave a slash or a gap between words. 20-8-1-14-11 25-15-21 reads THANK YOU.
If the message comes out as nonsense, try ticking Start at A = 0, since some puzzles count from zero. Any number that cannot be a letter, such as 27 or 0 in the normal system, is shown as a question mark and listed so you can check it.
When the numbers are not a simple A1Z26 code
Puzzle setters often add a twist. If the numbers are all between 1 and 26 but the letters still look scrambled, the setter may have shifted the alphabet first, so try the result in the Caesar cipher tool and press Try all 25 shifts.
Numbers from 65 to 90 or 97 to 122 are probably ASCII codes for capital and small letters, which the ASCII table explains. Pairs of numbers such as 3-14 may point to a page and a word in a book, which is a book cipher and needs the right book to solve.
For a message where you do not know the code at all, paste it into the cipher decoder, which tests letter numbers along with many other codes.
Questions and answers
How do I turn numbers into letters?
Paste them into the box. Each number from 1 to 26 becomes the letter in that place in the alphabet.
What does 8-5-12-12-15 mean?
HELLO: 8 is H, 5 is E, 12 is L and 15 is O.
Why is there a question mark in the result?
That number cannot be a letter in this code, for example 27 or above. It is listed under the result so you can check it.
What if my numbers start from 0?
Tick Start at A = 0 so that 0 is A and 25 is Z.