Encode or decode text with a Caesar cipher — one of the oldest and simplest classical ciphers. Shift each letter by a fixed number of positions through the alphabet.
0–25 positions through the alphabet
No letters to analyze.
English avg: E 12.7%, T 9.1%
Caesar cipher is a toy cipher easily broken by frequency analysis. Never use it for real security — use AES or modern encryption instead. It's great for puzzles, education, and hidden messages.