Solves Caesar/ROT, Atbash, affine, general and homophonic substitution, Vigenère/Beaufort, keyed-alphabet Vigenère (Quagmire, with the alphabet keyword), running key and transposition ciphers (rail fence, columnar, routes) on English text, also when written as numbers (A1Z26, ASCII codes) or hidden among nulls. Everything runs in your browser; nothing is sent anywhere.
Show answer
Best plaintext
Statistics
Key cipher letter → plain letter. Edit a letter to fix it (it gets locked), then re-solve to search the rest.
Cipher ABCDEFGHIJKLMNOPQRSTUVWXYZ
Plain
Encryption key (plain ABC…Z → cipher):
Keyword edit it to see the effect immediately
Symbol mapping symbol → plain letter (count in brackets). Edit a letter to fix it (it gets locked), then re-solve to search the rest.
Key stream
Both streams with the word breaks found click a word in the first line to swap the two streams from that word on
Running key output from the automatic solver is only partly right. It looks for a plaintext and a key that are both English, but it cannot tell which of the two English streams is the message, so it often swaps them for stretches of text. With "Work harder" set to hard or very hard, most letters are usually right in one stream or the other: click a word to swap the streams from there, or use cribs (words you expect) to lock parts and re-solve.
Crib dragging
Position
Other stream
Score
Locked fragments
none
Candidates ranked by English likelihood (quadgram log10 score; higher is better). Click one to view it.