Tools

Caesar cipher and Morse code

Encrypt or decrypt with the Caesar cipher (any shift), ROT13, ROT47 or Atbash, or encode and decode international Morse code.

Process locally

Files stay in this browser session. Closing or clearing releases them.

Import recipe

Add text

Type or paste the text to process

Adjust settings

Optional: Cipher, Direction, Caesar shift

CipherDirectionCaesar shift

Run

Processes in this browser; cancel at any time

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About this tool

Encrypt and decrypt text with the Caesar cipher, ROT13, ROT47 or Atbash, or translate text to and from international Morse code. It is handy for puzzles and escape-room clues, for teaching how classical ciphers work, or for reading a ROT13 spoiler someone posted.

The Caesar shift can be 1 to 25, letters keep their case, and characters a cipher does not cover, such as Chinese, stay as they are. Morse code covers A–Z, 0–9 and common punctuation, with letters separated by spaces and words by “ / ”. Up to 1 MB of text is processed in your browser and not uploaded.

How to use it

Type or paste the text, or select Use example.
Choose a “Cipher” and a “Direction”: “Encrypt or encode” or “Decrypt or decode”.
For the Caesar cipher, set the “Caesar shift” (3 by default).
Select Run, preview the result and download it.

Formats and limits

Input: Text
Output: Plain text
Size limit: 1 MB
Settings: Cipher (Caesar cipher, ROT13, ROT47, Atbash, Morse code); Direction (Encrypt or encode, Decrypt or decode); Caesar shift
Privacy: Files stay in the current browser session. No file bytes are uploaded.
Price: Free, no sign-up

Common questions

Do ROT13, ROT47 and Atbash need a direction?

No. Each of them is its own inverse, so running the result through again restores the text, whichever direction is selected. Only the Caesar cipher and Morse code use the direction.

Which characters change?

Caesar, ROT13 and Atbash change only the letters A–Z and a–z and keep their case. ROT47 also rotates digits and punctuation, every printable ASCII character except the space (codes 33 to 126). Spaces, line breaks and Chinese characters stay as they are.

How should Morse code be written for decoding?

Use dots and dashes, with a space between letters and / or | between words; three or more spaces also separate words. Dots written as · or • and dashes written as – or — are accepted too. The decoded text is in capital letters.

Why does Morse encoding report an unsupported character?

Morse code covers A–Z, 0–9 and a set of punctuation such as . , ? / @ ( ), but not Chinese characters or other symbols, and the error names the first character it cannot encode. Line breaks count as spaces, so the output is a single line with / between words.

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