Caesar Cipher / ROT13
Encode or decode text with a Caesar shift. For learning, not real security. Free, private and instant.
About the Caesar Cipher / ROT13
The Caesar cipher shifts each letter by a fixed number of places. ROT13 is the special case with a shift of 13, which is its own reverse.
When to use it
Use it for puzzles, teaching and hiding spoilers. It offers no real security and is trivially broken.
How to use the Caesar Cipher / ROT13
- Enter or paste your input in the fields above.
- The result updates as you type, or press Run.
- Press Copy to copy the output.
Frequently asked questions
Is the Caesar Cipher / ROT13 free?
Yes. It is completely free, with no signup and no usage limits.
Is my data uploaded anywhere?
No. Everything runs locally in your browser, so what you type never leaves your device.
Does the Caesar Cipher / ROT13 work on mobile?
Yes. The tool is responsive and works on phones, tablets and desktops.
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