BYTETOOLS

Text Cipher

Encrypt and decrypt text with Caesar shift, ROT13 and Vigenère ciphers. Preserves case and punctuation. Free, private, in-browser cipher tool.

  • Caesar cipher with adjustable shift
  • One-click ROT13 encoding and decoding
  • Vigenère cipher with a custom keyword
  • Preserves case, spaces and punctuation
  • 100% private — text never leaves your browser
  • Free, no sign-up, works offline as a PWA

How to use the Text Cipher

  1. 1

    Choose a cipher: Caesar, ROT13 or Vigenère.

  2. 2

    Set the shift amount or keyword if the cipher needs one.

  3. 3

    Toggle between Encrypt and Decrypt.

  4. 4

    Type your message and copy the transformed result.

About the Text Cipher

The ByteTools Text Cipher encodes and decodes messages using three classic substitution ciphers: Caesar with a selectable shift, the famous ROT13, and the keyword-based Vigenère cipher. Switch direction to encrypt or decrypt in one click.

Letter case is preserved and non-letters like spaces, numbers and punctuation pass through untouched, so your ciphertext keeps the original shape of the message. It is great for puzzles, learning cryptography basics and light-hearted secret notes.

All encryption runs locally in your browser with JavaScript. Nothing is uploaded or stored — but remember these are historical ciphers meant for fun and education, not real security.

Frequently asked questions

What is the difference between Caesar and ROT13?

ROT13 is simply a Caesar cipher with a fixed shift of 13. Because the alphabet has 26 letters, applying ROT13 twice returns the original text, which makes it a handy self-reversing cipher for hiding spoilers.

How does the Vigenère cipher work?

Vigenère shifts each letter by an amount taken from a repeating keyword, so the same letter can encrypt differently depending on its position. Decrypting requires the same keyword you used to encrypt.

Does the cipher keep my spaces and punctuation?

Yes. Only letters are shifted; spaces, digits and punctuation are left exactly as they are, and upper and lower case are preserved. This keeps the ciphertext readable and easy to line up with the original.

Are these ciphers secure?

No. Caesar, ROT13 and Vigenère are historical ciphers that are trivial to break with modern methods. Use them for puzzles, games and learning, never for protecting real passwords or sensitive information.

Is my message uploaded when I encrypt it?

No. All encryption and decryption happens in your browser with JavaScript. Nothing is sent to a server or stored, so your messages stay entirely on your device.

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