ROT47 Encoder / Decoder
What is ROT47?
ROT47 is a simple letter substitution cipher that replaces each printable ASCII character with another character
by rotating it 47 positions forward in the ASCII table. It covers the range from ! (33) to ~ (126),
giving a total of 94 characters. Because the shift is exactly half of that range, applying ROT47 twice returns the original text,
making the same function both encode and decode.
ROT47 vs ROT13
While ROT13 only rotates letters (A-Z, a-z) and leaves numbers and symbols untouched, ROT47 transforms almost all visible keyboard characters. This makes it slightly more useful for obfuscating text that contains digits and punctuation, but it is equally insecure for any real encryption.
How ROT47 works
The algorithm can be described mathematically:
For each character c (33 ≤ c ≤ 126):
new_char = 33 + ((c - 33 + 47) % 94)
Characters outside the 33–126 range (like spaces, newlines, or control codes) remain unchanged.
Use cases of ROT47
- Simple text obfuscation – Hiding spoilers, puzzle clues, or answers in forums.
- CTF (Capture The Flag) challenges – Frequently appears in cybersecurity competitions.
- Learning cryptography basics – Helps beginners understand substitution ciphers.
- Encoding URLs or code snippets – Quick way to disguise information without real encryption.
Is ROT47 secure?
No. ROT47 is a trivial substitution cipher with zero security. It can be broken instantly by anyone who knows the algorithm or even by simple brute force. Never use it to protect sensitive data. It's meant only for fun, education, or light obfuscation.
Why use this online tool?
- Instant conversion with a single click
- Copy result to clipboard easily
- Real-time character count
- Works on mobile and desktop without any installation
- Completely free and respects your privacy (no data sent to server)
Start typing above and see the magic of ROT47!
