Caesar, ROT13, ROT47, Atbash and Vigenère Cipher Tool

How to use it

Type the text in Text.
Choose the Cipher, and for Caesar and Vigenère the Direction and the Alphabet.
Set the Shift or the Keyword that the cipher needs.
Copy the Result. When the shift is unknown, read the rows of Every Caesar shift until one makes sense.

How each cipher works

Caesar moves each letter a fixed number of places along the alphabet; the shift is the key. The Wikipedia article's example uses a shift of three.
ROT13 is Caesar with a shift of 13. The alphabet has 26 letters, so applying ROT13 twice gives the text back.
ROT47 moves the printable characters 33 to 126 (letters, digits and common marks) by 47 places, so digits and punctuation change too.
Atbash writes the alphabet backwards: A becomes Z, B becomes Y, and so on.
Vigenère shifts each letter by the next letter of a keyword, so the same letter can change in different ways.

The Turkish alphabet

The Turkish alphabet has 29 letters: A B C Ç D E F G Ğ H I İ J K L M N O Ö P R S Ş T U Ü V Y Z. It has no Q, W or X. The dotted and the dotless i are two letters, I and İ, so a shift moves through all 29 of them and Z is followed by A.

Characters outside the chosen alphabet stay as they are: with the Turkish alphabet, a Q or a W is not moved.

What these ciphers are not

They do not protect a secret. A Caesar text is broken by trying every shift, which the table of all shifts shows at once.
A short keyword makes Vigenère easy to break by counting letters, so do not rely on it for anything private.
Nothing is stored or sent: the text is changed in your browser.

Worked example: ATTACKATDAWN with the keyword LEMON

The letters of LEMON give the shifts 11, 4, 12, 14 and 13 (L is 11 places after A, E is 4, and so on). The first letter A is moved by L, so it becomes L. The second letter T is moved by E, so it becomes X. The result of the whole text is LXFOPVEFRNHR, and the same keyword decodes it.

Letter	Shift from the keyword	Result
A	L (11)	L
T	E (4)	X
T	M (12)	F
A	O (14)	O

Frequently asked questions

Is ROT13 a safe way to hide a text?

No. Its shift is fixed and known to everybody, so anyone who sees a ROT13 text can read it in one step. It is used to hide spoilers and puzzle answers, not secrets.

How do I break a Caesar cipher?

Try every shift. The table of every shift shows the decoded text for each of the 25 shifts of the English alphabet, or the 28 of the Turkish alphabet; the one that reads as ordinary language is the answer.

Why does the Turkish alphabet give other results than the English one?

The Turkish alphabet has 29 letters, so the same shift lands on other letters. A shift of 1 turns C into D in English but into Ç in Turkish, and it turns ı into i. Use the alphabet the text is written in.

Does the tool send my text to a server?

No. The encoding and decoding run in your browser, and the text is not stored or sent to our server.

Why does ROT47 change digits and punctuation as well?

ROT47 moves the printable characters from ! to ~ by 47 places, so letters, digits and common marks all change. Applying it twice gives back the original text.

Sources

Figures and text last checked on Tuesday, November 10, 2026.

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