Can ROT13 encrypt numbers or punctuation?

No. ROT13 only transforms the letters A–Z. Numbers, emojis, and punctuation stay unchanged.

No. ROT13 is not meant for security. It is only for light obfuscation or puzzle-related fun.

ROT13 Cipher

Q: What does ROT13 stand for?

ROT13 means Rotate by 13. Each letter is shifted 13 places through the alphabet.

Q: Is ROT13 the same as the Caesar Cipher?

Yes, ROT13 is a special case of the Caesar Cipher with a fixed shift of 13.

ROT13 the classic rotate-by-13 Caesar cipher variant has been used online for decades – hiding spoilers, masking punchlines, or giving puzzle fans a tiny bit of mystery before they inevitably decode it anyway. Not secure, but definitely fun.

Text to Encode/Decode Press Enter to encode, Shift+Enter for new line

Result

ROT13 Cipher

What is ROT13?

ROT13 (“rotate by 13 places”) is a special case of the classic Caesar Cipher. Instead of selecting your own shift, ROT13 always rotates each letter exactly 13 positions through the alphabet. Because the alphabet has 26 letters, applying ROT13 twice returns the text back to normal. It’s encryption… but with training wheels.

How ROT13 Works

ROT13 is simply the Caesar Cipher with a fixed key:

ROT13 = Caesar shift of 13

This means:

HELLO   →   URYYB  
            URYYB   →   HELLO

Alphabet Mapping

Letter	ROT13	Letter	ROT13
A	N	N	A
B	O	O	B
C	P	P	C
D	Q	Q	D
E	R	R	E
F	S	S	F
G	T	T	G
H	U	U	H
I	V	V	I
J	W	W	J
K	X	X	K
L	Y	Y	L
M	Z	Z	M

Examples

Input:

The treasure is buried under the apple tree.

ROT13 Output:

Gur gernfher vf ohevrq haqre gur nccyr gerr.

Related Cipher Tools

If you're exploring classical substitution ciphers, these tools may also be useful:

Frequently Asked Questions

What does ROT13 stand for?

It means “Rotate by 13”. Each letter is shifted 13 places through the alphabet.

Is ROT13 the same as the Caesar Cipher?

Yes. ROT13 is simply a Caesar Cipher with a fixed shift of 13.

Can ROT13 encrypt numbers?

No. ROT13 only works on letters A–Z. Numbers, punctuation, emojis and symbols don’t change.

Is ROT13 secure?

Not at all. It’s just for light obfuscation and puzzle fun.