Caesar Cipher — Encrypt & Decrypt
Encrypt and decrypt text using the Caesar cipher with adjustable shift. Supports Latin and Cyrillic alphabets with brute-force decryption.
How to Use the Caesar Cipher — Encrypt & Decrypt
- Enter or paste your text in the input field.
- The encoded or decoded result appears automatically.
- Copy the output using the copy button.
- Switch between encode and decode modes if available.
Quick Reference
| From | To |
|---|---|
| A (shift 3) | D |
| HELLO (shift 1) | IFMMP |
| Z (shift 3) | C |
| ABC (shift 13) | NOP |
| TEST (shift 5) | YJXY |
| CODE (shift 7) | JVKL |
Use Cases
- •Encoding or decoding data for web development projects.
- •Learning about cryptography and different cipher techniques.
- •Preparing encoded content for APIs or data transmission.
- •Solving cipher puzzles, CTF challenges, or educational exercises.
Formula
Caesar cipher shifts each letter by N positions in the alphabet. Encryption: E(x) = (x + n) mod 26. Decryption: D(x) = (x − n) mod 26.
Frequently Asked Questions
What is the Caesar cipher?
The Caesar cipher is one of the oldest encryption methods. Each letter in the plaintext is shifted by a fixed number of positions in the alphabet. It is named after Julius Caesar, who used it in his correspondence.
How do I decrypt without knowing the shift?
Use the brute-force method: try all 25 possible shifts and look for the one that produces readable text. Since there are only 25 variants, this is easy to do manually or automatically.
Does the Caesar cipher work with Cyrillic?
Yes. This tool supports both the Latin (26 letters) and Cyrillic (33 letters) alphabets. Each alphabet is shifted independently.
Is the Caesar cipher secure?
No. The Caesar cipher is trivially broken by brute force (only 25 keys) or frequency analysis. It is used for educational purposes, not real security.