ClickyFix

ROT13 Encoder/Decoder

Free

Encode and decode text using ROT13, ROT5, ROT18, ROT47, or custom rotation ciphers.

Cipher Information

ROT13

Shifts letters by 13 positions. A becomes N, B becomes O, etc. Encoding and decoding use the same operation.

A-M → N-Z, N-Z → A-M

ROT5

Shifts numbers by 5 positions. 0 becomes 5, 1 becomes 6, etc. Only affects digits 0-9.

0-4 → 5-9, 5-9 → 0-4

ROT18

Combination of ROT13 and ROT5. Encodes both letters and numbers.

ROT13(letters) + ROT5(numbers)

ROT47

Shifts all printable ASCII characters (33-126) by 47 positions. Includes letters, numbers, and symbols.

All ASCII 33-126 shifted by 47

About ROT Ciphers

ROT (rotate) ciphers are simple letter substitution ciphers that replace each letter with another letter a fixed number of positions down the alphabet. ROT13 is the most famous, as it's its own inverse - applying it twice returns the original text. These ciphers provide no real security but are useful for hiding spoilers, puzzle answers, or offensive content from casual viewing.

How to Use the ROT13 Tool

  1. Select the cipher type (ROT13, ROT5, ROT18, ROT47, or Custom)
  2. Enter your text in the input area
  3. The encoded/decoded result appears automatically
  4. Use "Swap" to quickly encode the output again
  5. Copy the result to use elsewhere

Features

  • ROT13 (letters shifted by 13)
  • ROT5 (numbers shifted by 5)
  • ROT18 (ROT13 + ROT5 combined)
  • ROT47 (all ASCII characters)
  • Custom shift amount (1-25)
  • Real-time encoding/decoding

What is ROT13?

ROT13 ("rotate by 13 places") is a simple letter substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet. Because there are 26 letters, applying ROT13 twice returns the original text.

Example: "HELLO" becomes "URYYB"

ROT13 was popularized on Usenet forums in the 1980s to hide spoilers, puzzle answers, and potentially offensive content from casual viewing. It provides no cryptographic security but serves as a simple "content warning" mechanism.

Common Use Cases

  • Hiding spoilers: Encode movie/book spoilers in forums
  • Puzzle answers: Hide answers to riddles or puzzles
  • Email obfuscation: Hide email addresses from simple scrapers
  • Learning: Introduction to substitution ciphers
  • CTF challenges: Common in capture-the-flag competitions

ROT Cipher Variants

ROT5: Same concept as ROT13 but for numbers only. Shifts digits by 5 (0→5, 1→6, ..., 5→0, 6→1, etc.).

ROT18: Combines ROT13 for letters and ROT5 for numbers, encoding both in a single operation.

ROT47: Uses all 94 printable ASCII characters (codes 33-126), shifting by 47. This encodes letters, numbers, and symbols.

Custom ROT: Also known as a Caesar cipher, allows any shift value from 1-25. ROT13 is just a Caesar cipher with shift=13.