Transforms & generators
Caesar cipher tool
The classic rotation cipher. Pick a shift, encode or decode, keep punctuation.
Processed in your browser — nothing is uploaded
Only A–Z rotate. Shift is taken modulo 26. Decode applies the inverse.
Last reviewed 2026-09-10.
FAQ
Questions, answered
Is ROT13 a Caesar cipher?
Yes, with shift 13. There is also a dedicated ROT13 tool.
Numbers?
They are left unchanged.
Does my text leave the browser?
No. The Caesar cipher tool runs in JavaScript on this page. Your paste is not uploaded.
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