Cipher Decoder
Decode ROT13, Caesar, and Base64 text locally in your browser.
13
ROT13
hello world
Caesar (13)
hello world
Base64 decode
º¼²n6ÞÊ
Frequently Asked Questions
Is this cipher decoder free to use?
Yes, the Cipher Decoder is completely free with no login, watermarks, or usage limits.
Does this tool send my text to a server?
No. All ROT13, Caesar shift, and Base64 decoding runs entirely in your browser using local JavaScript — nothing is uploaded or transmitted.
Which ciphers are supported?
The tool decodes ROT13, a Caesar cipher with an adjustable shift value (1–25), and Base64-encoded text simultaneously from a single input.
Can I use a custom shift value for the Caesar cipher?
Yes, use the shift slider to try any value from 1 to 25 and the Caesar output updates live.