Scream Cipher
A substitution cipher for the 26-letter English alphabet.
It was made by xkcd.com, seemingly as a joke based on the fact that all text in Scream Cipher looks kind of like screaming.
You can see the original webcomic here.
The cipher appeared in an xkcd web comic released on February 21st, 2025. The comic featured an image displaying the cipher with one person texting "A̰ÁĂĂÅ" to another, who replies "A̰Ả".
The image comic featured the following mouseover text: "AAAAAA A ÃA̧AȂA̦ ǍÅÂÃĀÁȂ AAAAAAA!"
The comic also featured the following mouseover text: "In the Scream Cipher, messages consist of all As, with different letters distinguished using diacritics."
Below is the scream cipher in a table.
| English | Scream | HTML |
| A | A | A |
| B | Ȧ | Ȧ |
| C | A̧ | A̧ |
| D | A̱ | A̱ |
| E | Á | Á |
| F | A̮ | A̮ |
| G | A̋ | A̋ |
| H | A̰ | A̰ |
| I | Ả | Ả |
| J | A̓ | A̓ |
| K | Ạ | Ạ |
| L | Ă | Ă |
| M | Ǎ | Ǎ |
| N | Â | Â |
| O | Å | Å |
| P | A̯ | A̯ |
| Q | A̤ | A̤ |
| R | Ȃ | Ȃ |
| S | Ã | Ã |
| T | Ā | Ā |
| U | Ä | Ä |
| V | À | À |
| W | Ȁ | Ȁ |
| X | A̽ | A̽ |
| Y | A̦ | A̦ |
| Z | A̷ | A̷ |
I'm not too sure about my transciption of the character for "Z", but it's good enough --and at least that encoding isn't ambiguous. So yeah. Scream folks.