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How to use ROT18 Cipher

Enter text and the ROT18 output updates live. Letters shift 13 places and digits shift 5; running the result back through the tool restores the original.

Frequently asked questions

What is ROT18?

A combination cipher: letters use ROT13 and digits use ROT5. It obscures both text and numbers while staying its own inverse.

Why combine ROT13 and ROT5?

Plain ROT13 leaves digits unchanged. ROT18 also scrambles 0-9, which is handy when the content mixes words and numbers.

Is it reversible without a key?

Yes — like ROT13, applying ROT18 a second time returns the original, so no key is required.

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