๐Ÿ”“ Caesar Cipher Cracker

Best guess (shift: 3)

The quick brown fox jumps over the lazy dog

Show all shifts (25 options)
3The quick brown fox jumps over the lazy dog
9Nby kocwe vliqh zir dogjm ipyl nby futs xia
15Hvs eiwqy pfckb tcl xiadg cjsf hvs zonm rcu
19Dro aesmu lbygx pyh tewzc yfob dro vkji nyq
5Rfc osgai zpmul dmv hsknq mtcp rfc jyxw bme
16Gur dhvpx oebja sbk whzcf bire gur ynml qbt
2Uif rvjdl cspxo gpy kvnqt pwfs uif mbaz eph
12Kyv hlztb sifne wfo aldgj fmvi kyv crqp ufx
22Aol xbpjr iyvdu mve qbtwz vcly aol shgf kvn
14Iwt fjxrz qgdlc udm yjbeh dktg iwt apon sdv
25Xli uymgo fvsar jsb nyqtw sziv xli pedc hsk
4Sgd pthbj aqnvm enw itlor nudq sgd kzyx cnf
6Qeb nrfzh yoltk clu grjmp lsbo qeb ixwv ald
13Jxu gkysa rhemd ven zkcfi eluh jxu bqpo tew
7Pda mqeyg xnksj bkt fqilo kran pda hwvu zkc
21Bpm ycqks jzwev nwf rcuxa wdmz bpm tihg lwo
10Max jnbvd ukhpg yhq cnfil hoxk max etsr whz
11Lzw imauc tjgof xgp bmehk gnwj lzw dsrq vgy
23Znk waoiq hxuct lud pasvy ubkx znk rgfe jum
17Ftq cguow ndaiz raj vgybe ahqd ftq xmlk pas
24Ymj vznhp gwtbs ktc ozrux tajw ymj qfed itl
20Cqn zdrlt kaxfw oxg sdvyb xena cqn ujih mxp
1Vjg swkem dtqyp hqz lworu qxgt vjg ncba fqi
18Esp bftnv mczhy qzi ufxad zgpc esp wlkj ozr
8Ocz lpdxf wmjri ajs ephkn jqzm ocz gvut yjb

Enter Caesar-cipher ciphertext with an unknown shift, and this tool automatically guesses the most likely shift using frequency analysis โ€” comparing each of the 25 possible decodings against standard English letter frequencies. All 25 results are also available to compare directly.

How to use

  1. Enter the ciphertext you want to crack.
  2. The top guess (whichever shift looks most like English by frequency analysis) is shown automatically.
  3. Open "Show All Shifts" to compare all 25 possible decodings side by side.

FAQ

How does frequency analysis work?

English text has predictable letter frequencies (e.g. 'e' and 't' are common), so this tool picks whichever of the 25 possible shifts produces a letter distribution closest to standard English as its top guess.

Does this work reliably on short text?

Shorter text has more statistical noise, so an incorrect shift can sometimes rank first. Longer text (a few dozen characters or more) gives more reliable results.

Does this work on non-English ciphertext?

No, frequency analysis here is based on English letter frequencies, so it only works on English (Latin-alphabet) text.