Classic Ciphers

Three free tools for exploring or applying classic ciphers. ROT13 Encoder shifts letters, Caesar Cipher uses a numeric key and Morse code turns letters and digits into signals. They work well for puzzles, workshops, exercises and playful messages. You can try a simple substitution, a shift or dots and dashes without installing anything. Everything runs in your browser, with no sign-up.

Your choice depends on the method you need. ROT13 is a fixed substitution, handy for making text less readable at a glance. Caesar Cipher lets you set a precise shift. Morse code encodes or decodes letters and digits. Start with the tool whose name matches the code you are using.

How to use

  1. Start with the required code: fixed substitution, a shift with a numeric key, or signals for letters and digits. ROT13 Encoder, Caesar Cipher and Morse code match those three cases.
  2. For simple reversible obfuscation, open ROT13 Encoder and apply it once; apply it again to return to readable text.
  3. For an exercise with a key, use Caesar Cipher, record the key you choose and keep it to decode the message.
  4. For dots and dashes, choose Morse code, enter letters and digits, then check the direction before sending.

Frequently asked questions

Do these ciphers really protect a message?

No, these classic methods are simple and well known. They fit games, exercises or casual obfuscation, not the protection of sensitive data. For serious security, use dedicated security tools.

Can I decode text with these tools?

ROT13 and Morse code can be used in both directions depending on the tool. Caesar Cipher needs the same numeric key to recover the text. Check the result before reusing it.

Which tool should I use to hide text without choosing a key?

ROT13 Encoder is made for that: it applies a fixed substitution to the text. The same action brings the message back to its original form. For an adjustable shift, use Caesar Cipher, which asks for a numeric key.

How do I recover text encoded with Caesar Cipher?

You must reuse the same numeric key that was used for encoding. Write down that key when you encode, then enter it in Caesar Cipher to decode. Without the correct key, the result stays unreadable.

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