ROT18 a String
Rotate letters by 13 and digits by 5: ROT13 plus ROT5. Runs entirely in your browser, so your data never leaves your device.
0 chars · 0 lines
Output
The result appears here as you type.
How to use ROT18 a String
- 1. Paste your text. Enter text that includes both letters and digits into the input pane, such as Hello 123, since ROT18 only has an effect on those two character types.
- 2. Read how the cipher works. There are no settings; letters are rotated 13 places as in ROT13, and digits are rotated 5 places as in ROT5, while everything else stays exactly as typed.
- 3. Copy the transformed text. Copy the result from the output pane, such as Uryyb 678, and reuse the same tool to reverse it since applying ROT18 twice restores the original text.
When to use ROT18 a String
ROT18 a String combines ROT13 for letters with ROT5 for digits, so a mixed alphanumeric string like a serial number or a coded phrase gets both parts obscured together in one pass. Reach for it whenever ROT13 alone isn't enough because the text contains meaningful numbers too.
- Obscuring a coded message that includes numbers. A puzzle answer combines a word and a number, like a room code or a combination, and plain ROT13 would leave the digits readable. ROT18 obscures both parts together.
- Hiding a spoiler that references a specific date or count. A forum spoiler mentions a specific chapter number or year alongside plot details. ROT18 keeps both the words and the numbers from being readable at a glance.
- Testing a combined letter-and-digit rotation cipher. You're studying classic rotation ciphers and want to see how ROT13 and ROT5 behave together on a single string that mixes letters and numbers.
- Encoding an alphanumeric code for a lighthearted reveal. A trivia game wants to hide an alphanumeric answer, like a product code, until players choose to decode it themselves using the same rotation.
Examples
ROT18
Input
Hello 123
Output
Uryyb 678
About the ROT18 a String tool
ROT18 a String runs as plain JavaScript in your browser tab, with no server behind it. Rotate letters by 13 and digits by 5: ROT13 plus ROT5. Whatever you put in stays on your device from start to finish.
The tool is part of EditSafely's String Tools section, 159 single-purpose utilities built around the same idea: open the page, get the result, keep your data to yourself.
There is nothing to configure. Provide the input and the result appears on its own. A worked example further down the page shows exactly what the tool produces for a real input.
That local-first design has practical benefits beyond privacy. The tool keeps working on a flaky connection once the page has loaded, results are instant because nothing round-trips to a server, and it is safe to use with confidential material.
Frequently asked questions
Is ROT18 a String free to use?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Is it safe to paste sensitive or confidential data?
Everything happens locally. Your browser downloads the tool's code once, then does all the processing itself; nothing you enter is transmitted, stored or logged. You can even go offline after the page loads and it will still work.
How much text can I process at once?
There is no fixed limit. Because the work happens on your own device rather than on a shared server, the practical ceiling is your machine's memory, which comfortably handles inputs far larger than typical online tools allow.
Do I need to sign up or install anything?
No. The tool works in any modern browser on desktop, tablet or phone. There is no account to create, no extension to add and no software to install.
How do I use the result?
The output panel has a one-click copy button, and you can keep refining the input while you work; the result updates in place as you type.