ROT47 encoder and decoder
Paste text to scramble it with ROT47, or paste ROT47 text to read it — the same operation does both. ROT47 shifts all 94 visible ASCII characters, so digits and punctuation change too, unlike ROT13. ROT18 and ROT5 variants are included.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Type or paste the text. The result updates as you type.
- Choose ROT47, ROT18 or ROT5.
- Copy the result. To decode, paste the scrambled text and use the same cipher.
How it works
ROT47 works on the 94 printable ASCII characters from ! (code 33) to ~ (code 126). Each one moves 47 places forward, wrapping around at the end:
c′ = 33 + (c − 33 + 47) mod 94
Spaces, line breaks and characters outside ASCII (accented letters, Cyrillic, emoji) are left unchanged. ROT5 uses the same idea on the ten digits with a shift of 5; ROT18 is ROT13 on A–Z and a–z plus ROT5 on 0–9.
Worked example
H has code 72: 33 + (72 − 33 + 47) mod 94 = 33 + 86 = 119, which is w. The letter e (101) becomes 33 + (115 mod 94) = 54, the digit 6. Doing this for the whole phrase gives:
Hello, World! → w6==@[ (@C=5P
Running ROT47 on w6==@[ (@C=5P gives Hello, World! again.
Tips
- Text that looks like random symbols with no spaces changed, such as
w6==@[, is often ROT47.
- Only ASCII changes, so text in other alphabets stays readable — ROT47 is no use for hiding it.
- For a letter-only shift with any key from 1 to 25, use the Caesar cipher tool.
Frequently asked questions
How do I decode ROT47?
Run it through ROT47 again. The printable ASCII range has 94 characters and 47 is exactly half of 94, so shifting twice brings every character back: w6==@[ (@C=5P turns back into Hello, World!.
What is the difference between ROT13 and ROT47?
ROT13 only rotates the 26 Latin letters by 13 and leaves digits and symbols alone. ROT47 rotates every visible ASCII character from ! (code 33) to ~ (code 126), so numbers, punctuation and letters all change and the result looks less like words.
What are ROT5 and ROT18?
ROT5 rotates only the digits by 5 (0 ↔ 5, 1 ↔ 6 …). ROT18 combines ROT13 for letters with ROT5 for digits, so Agent 007 becomes Ntrag 552. Both decode themselves, like ROT47.
Is ROT47 secure?
No. It has no key — anyone who knows it is ROT47 can read it at once. It only hides text from a casual glance, such as spoilers or puzzle answers. Use real encryption for anything private.