What is ROT13 used for?+
ROT13 is not encryption - it's obfuscation for casual spoiler hiding. It was popular on Usenet newsgroups for hiding puzzle answers and plot spoilers. Applying ROT13 twice returns the original text, so the same function encodes and decodes.
Does ROT13 change numbers or punctuation?+
No. ROT13 only shifts letters (A-Z and a-z). Numbers, punctuation, spaces, and other characters are passed through unchanged.
What is the difference between ROT13 and Caesar cipher?+
ROT13 is a specific Caesar cipher with a shift of 13. A Caesar cipher can use any shift value (1-25). ROT13's shift of 13 is special because the alphabet has 26 letters - applying it twice returns to the start, making it self-inverse.
Is ROT13 the same as Base64?+
No. ROT13 substitutes letters with other letters - it remains human-readable. Base64 encodes binary data as alphanumeric characters - the output looks like random text. Both are encodings, not encryption.