Cipher Tool

14 ciphers · analyze · brute force · generator · history · compare

Ciphers
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ROT13
Atbash
Vigenère
Rail Fence
Morse Code
Binary
Hexadecimal
Base64
Bacon's Cipher

Each letter becomes a 5-character code using two symbols (A and B by default).

Polybius Square

Letters become two-digit coordinates on a 5×5 grid (I and J share a cell).

Reverse
Null Cipher

Hides a message inside a longer text by taking specific letters from each word.

Custom Substitution

Map each letter to any character. The key is a 26-character string where position 1 = what A becomes, position 2 = what B becomes, etc.

Text Analysis
Letter Frequency
Index of Coincidence
Caesar Brute Force

Tries all 25 shifts. Click any result to copy it.

All shifts
Random Generator
Compare All Ciphers
Recent operations

Auto-logs every encode/decode. Click any item to copy its output.