Every Toolkit

ROT13 Cipher

Simple letter substitution cipher - Rotate text by 13 positions

ROT13 is its own inverse!

Applying ROT13 twice returns the original text. This makes it perfect for both encoding and decoding.

ROT13 Encoder/Decoder
Simple Cipher

Enter text to encode or decode using ROT13 rotation cipher

0 characters0 letters

ROT13 Alphabet Mapping

See how each letter is rotated by 13 positions

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

Original

A B C D E F G H I J K L M

ROT13

N O P Q R S T U V W X Y Z

Try These Examples

How ROT13 Works

1

Letter Rotation

Each letter is replaced by the letter 13 positions after it in the alphabet

A → N, B → O, C → P, etc.
2

Wraps Around

After Z, it wraps back to A (26 letters ÷ 2 = 13)

N → A, O → B, Z → M
3

Case Preserved

Uppercase and lowercase letters are handled separately

Hello → Uryyb
4

Non-letters Unchanged

Numbers, punctuation, and spaces remain the same

Hello, World! → Uryyb, Jbeyq!

About ROT13

  • • ROT13 is a simple letter substitution cipher
  • • It's a special case of the Caesar cipher with a shift of 13
  • • Applying ROT13 twice returns the original text (self-inverse)
  • • Not secure for real encryption - used for obscuring text like spoilers
  • • Commonly used in online forums to hide puzzle solutions or plot spoilers

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