Spell a word as its alphabet positions, or decode a list of numbers into text.
In the A1Z26 cipher each letter is replaced by its position in the alphabet, so A is 1, B is 2 and Z is 26. The tool detects what you pasted: if the input has letters it encodes them, and if it has only numbers it decodes them.
Letters of one word are joined with the separator you choose, and a slash marks the gap between words, so 8 5 12 12 15 / 23 15 18 12 4 reads hello world. Digits outside 1 to 26 are shown as a question mark during decoding.
No. It is a fixed substitution that anyone can reverse, so treat it as a puzzle tool and never as protection for private information.
Spaces between words become a slash in the encoded output, and the decoder turns a slash or a gap of three spaces back into a space.
Only the 26 basic Latin letters are encoded. Other characters are skipped.