Caesar Cipher / ROT13 Tool
Shift every letter in a text by a chosen amount, from a 1-letter shift up to a full ROT13, a classic substitution cipher.
Shift: 13
Input
Shifted (use shift 13 to reverse it)
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Frequently asked questions
Is this actually secure for hiding sensitive information?+
No, not remotely. A Caesar cipher has only 25 possible shifts, so it can be brute-forced by hand in seconds. It's a classic teaching example and a mild spoiler-hiding trick, not real encryption.
Why is ROT13 specifically special?+
13 is exactly half of 26, so applying ROT13 twice returns the original text; it's its own inverse. That's why it became a convenient, self-canceling way to obscure spoilers or punchlines in forum posts.
Does it change numbers or punctuation?+
No, only letters (A-Z, a-z) are shifted. Numbers, spaces, and punctuation pass through unchanged.