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Free ROT13 Encoder / Decoder

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Encode and decode text using ROT13, ROT47, and other Caesar ciphers.

Input (Plain Text)

0 characters

Output (ROT13)

0 characters

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

Each letter maps to the letter 13 positions ahead. A↔N, B↔O, C↔P, etc.

About ROT13 and Caesar Ciphers

ROT13 is a simple letter substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet. It's a special case of the Caesar cipher named after Julius Caesar who used similar ciphers for military communication.

Common Uses

  • Hiding spoilers in forums and discussions
  • Obscuring puzzle answers or punchlines
  • Simple email address obfuscation
  • Educational introduction to cryptography

Frequently Asked Questions

Common questions about ROT13 Encoder.

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What this tool does

Apply the reversible ROT13 letter substitution.

How to use it

Paste text; applying the operation again restores the original letters.

Worked example

Hello becomes Uryyb, and Uryyb becomes Hello.

Limitations and checks

Only Latin A–Z letters rotate. ROT13 offers no confidentiality and must not protect passwords or private messages.

How your data is processed

The operation runs in your browser. Copy and download actions use your device. Where Save work is offered, a local copy is stored; eligible work can sync only under your enabled account settings. See Privacy for site analytics and storage details.

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