ROT13 Encoder

Apply ROT13 to any text. Applying ROT13 twice restores the original.

ROT13 encode / decode tool

Convert text with ROT13

ROT13 uses the same operation for encoding and decoding. Applying it twice returns the original text.

Paste text here, for example: Hello BlinkCalc

ROT13 is reversible obfuscation, not encryption. Do not use it for passwords, secrets, API keys, or private data.

ROT13 output

Output is plain text and easy to copy.

Conversion status

Converted

ROT13 output is ready to copy. Numbers, punctuation, spaces, emojis, and non-Latin characters are preserved.

Status

Converted

ROT13 output is ready to copy. Numbers, punctuation, spaces, emojis, and non-Latin characters are preserved.

Input length

15

Characters in the input.

Output length

15

Characters in the ROT13 output.

Letters transformed

14

English A–Z and a–z letters rotated.

Characters preserved

1

Numbers, punctuation, spaces, emojis, and non-Latin characters.

Operation

ROT13 encode/decode

The same operation encodes and decodes.

Security level

Obfuscation only

ROT13 is not encryption.

Copy ROT13 output

Copy the converted text for puzzles, examples, spoilers, or documentation.

Swap output to input

Move the ROT13 output back into the input box to decode it again.

Copy original input

Copy the source text before transformation for comparison.

Privacy note

ROT13 conversion is designed to run locally in your browser without storing user input.

Accuracy note

Only English alphabet letters A–Z and a–z are rotated. Other characters are preserved.

Security note

ROT13 is instantly reversible and should not be used for secrets or sensitive information.

Practical ROT13 examples

Click an example to populate the encoder instantly.

ROT13 quick reference

A ↔ N

Uppercase A rotates to N and back again.

B ↔ O

Uppercase B rotates to O.

C ↔ P

Uppercase C rotates to P.

M ↔ Z

Uppercase M rotates to Z.

a ↔ n

Lowercase a rotates to n.

m ↔ z

Lowercase m rotates to z.

Symmetric

The same operation encodes and decodes.

Unchanged characters

Numbers, punctuation, spaces, emojis, and non-Latin characters are preserved.

ROT13 twice

Applying ROT13 twice restores the original text.

Text utility guide

Understand ROT13 encoding and decoding

ROT13 is a simple substitution cipher that rotates English alphabet letters by 13 positions. Since the alphabet has 26 letters, applying ROT13 twice restores the original text.

What is ROT13?

ROT13 is a simple letter substitution method that shifts each English alphabet letter by 13 positions. A becomes N, B becomes O, and N becomes A.

When should users use ROT13?

Use ROT13 for simple text obfuscation, spoiler hiding, puzzles, games, learning substitution ciphers, testing text transformation logic, and lightweight documentation examples.

ROT13 encode vs decode

ROT13 uses the same operation for encoding and decoding. Applying the tool again to ROT13 output returns the original text.

ROT13 vs encryption

ROT13 is not encryption. It has no secret key and can be reversed instantly by anyone. Do not use it for passwords, secrets, API keys, or private messages.

Privacy and security

BlinkCalc is designed to process ROT13 text locally in the browser. ROT13 output should still be treated as easily reversible.

Common ROT13 mistakes

Treating ROT13 as secure encryption.
Using it for passwords or secrets.
Expecting numbers or punctuation to change.
Expecting non-English characters to rotate.
Confusing ROT13 with Base64, hashing, or encryption.
Forgetting that applying ROT13 twice returns the original text.

How to use this ROT13 Encoder

  1. 1Paste or type text into the input box.
  2. 2Review the ROT13 output instantly or click Convert.
  3. 3Copy the converted text if needed.
  4. 4Use Swap or paste the output again to decode it back.
  5. 5Avoid using ROT13 for sensitive or private information.

Why developers use a ROT13 Encoder

Test simple text transformations.
Demonstrate reversible encoding.
Create puzzle or spoiler text.
Learn substitution cipher basics.
Confirm case-preserving character handling.
Quickly decode ROT13 examples found online.
Avoid manual letter shifting.

ROT13 Encoder FAQs

It shifts each English alphabet letter by 13 positions, turning A into N, B into O, and so on.