Caesar Cipher Encoder / Decoder
Encode or decode text with a classic Caesar shift cipher.
Results are provided for general informational use. Verify important financial, health or legal figures before relying on them.
About this Caesar Cipher Encoder / Decoder
The Caesar Cipher Encoder / Decoder shifts each letter in your text forward or backward through the alphabet by a chosen number of positions. It is one of the oldest known ciphers and is useful for puzzles, learning about cryptography basics or simple text obfuscation.
For related tasks, try Base64 Encoder / Decoder, URL Encoder / Decoder or Text to ASCII Converter.
How the calculation works
Each letter is moved a fixed number of positions through the alphabet, wrapping from Z back to A, while case is preserved and non-letter characters are left unchanged.
How to use it
- Paste your text and choose a shift amount.
- Select Encode to shift forward or Decode to shift back.
- Copy the transformed text.
Practical example
With a shift of 3, “HELLO” encodes to “KHOOR”. Decoding “KHOOR” with the same shift of 3 returns “HELLO”.
Frequently asked questions
Is a Caesar cipher secure?
No. It is easily broken and intended for education and simple puzzles rather than real security.
What happens with numbers or punctuation?
They are left unchanged; only letters are shifted.
Can I use a negative or large shift value?
Yes, any whole number works since the shift wraps around the 26-letter alphabet.
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