Caesar Cipher

Caesar Cipher Generator Online

Encrypt and decrypt messages using the classic Caesar cipher with any shift value. Perfect for puzzles, learning cryptography, and fun secret messages. Free.

How the Caesar Cipher Works

The Caesar cipher shifts each letter by a fixed number of positions: with shift 3, A→D, B→E, etc. Named after Julius Caesar who used it for military messages, it has only 25 possible keys for English and provides no modern security.

This tool encrypts and decrypts text using Caesar shift. It's useful for educational purposes and casual puzzles.

Example

Input: ABC (shift 3)
Output: DEF

How Encoding Works

All encoding and decoding runs locally in your browser using JavaScript. No data is sent to any server. The output is standard text that can be copied and pasted anywhere.

Platform Compatibility

This output uses standard Unicode characters and works on:

• Discord — fully supported in usernames, channel names, and messages
• Instagram — works in bio, name, and captions
• TikTok — works in bio and video descriptions
• Twitter/X — works in display name and bio (not all styles in tweets)
• Facebook — works in bio and About section
• YouTube — works in channel description and comments
• Twitch — works in chat and panel descriptions

If characters appear as empty boxes (□), the device may need an OS update for full Unicode font support.