Encode and decode ciphers free: Caesar, ROT13, Atbash and Base64. Type your text, pick a cipher and direction, and get the result instantly in your browser.
Choose a cipher and a direction, then press Convert. Caesar shifts every letter by your chosen amount (3 is the classic). ROT13 is Caesar with a fixed shift of 13, applied the same way both directions. Atbash mirrors the alphabet (A becomes Z, B becomes Y). Base64 is not a cipher but an encoding that turns any text, including Unicode, into plain ASCII safe for URLs and data fields.
These are classical ciphers for puzzles, learning and fun, not for protecting real secrets. Caesar, ROT13 and Atbash can be broken by hand in minutes. Never use them for passwords or private data; modern encryption like AES is what protects information for real.