Caesar Cipher Encoder - Shift Text by Any Amount

Encode text with Caesar cipher using any shift value. Classic letter substitution from 1-25 positions. Educational cryptography tool, instant results.

Input Text

Cipher Settings

Shift Amount: 3

1 13 (ROT13) 25

Output

Cipher Alphabet

Plain alphabet:

↓ Shift +3

Brute Force All Shifts

Quick Shift Reference

Shift 1: A→B (minimal)

Shift 3: A→D (Caesar's original)

Shift 13: A→N (ROT13)

Shift 25: A→Z (reverse -1)

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Frequently Asked Questions

The Caesar cipher is one of the oldest encryption techniques, shifting each letter by a fixed number of positions in the alphabet. Named after Julius Caesar who used it for military messages with a shift of 3.

Each letter moves forward (or backward) by the shift amount. With shift 3: A→D, B→E, C→F. When reaching Z, it wraps to A. So X→A, Y→B, Z→C with shift 3.

No. With only 25 possible shifts, it's trivially broken by trying all possibilities (brute force) or using frequency analysis. It's a learning tool, not real encryption. Never use it for sensitive data.

ROT13 is Caesar cipher with a fixed shift of 13. It's self-reversing (encoding twice decodes). Caesar cipher lets you choose any shift from 1-25, offering more variations but still no real security.

Shift in the opposite direction. If encoded with +5, decode with -5 (or +21, which is equivalent). Or try all 25 shifts - the one producing readable text is correct.

Only letters A-Z are shifted. Numbers, spaces, punctuation, and special characters remain unchanged. This makes Caesar cipher vulnerable to context analysis.

Yes. Shift -3 is the same as shift +23 (26-3). Negative shifts move backward through the alphabet: A→X, B→Y, C→Z with shift -3.

Breaking Caesar cipher by analyzing letter frequency. In English, 'E' is most common. If 'H' appears most in ciphertext, the shift is likely 3 (E→H). This breaks all substitution ciphers.

Julius Caesar used shift 3 for military correspondence. It persisted through medieval times for simple privacy. Replaced by more complex ciphers by the Renaissance, though variations existed until WW1.

Only for education. Caesar cipher teaches basic encryption concepts: substitution, keys, and why simple ciphers fail. Modern encryption (AES, RSA) uses mathematical complexity, not letter shifting.