Caesar Cipher
Shift letters with an adjustable Caesar cipher. Slider from 0 to 25 — includes ROT13 at shift 13.
Shift each letter by the selected amount. To decode, use shift 23 (or rotate the slider).
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Frequently Asked Questions
Quick answers to common questions
What is a Caesar cipher?+
Each letter shifts forward in the alphabet by a fixed number. Shift 3 turns A into D and Z into C.
How do I decode?+
Apply the reverse shift. If you encoded with shift 3, decode with shift 23 (or 26 minus your shift).
What is ROT13?+
ROT13 is a Caesar cipher with shift 13. Because 26 ÷ 2 = 13, applying it twice returns the original text.
Are numbers and symbols changed?+
No. Only A–Z and a–z are shifted. Everything else stays the same.
Is this secure encryption?+
No. Caesar cipher is a classic puzzle cipher — trivial to break. Do not use for secrets.
Can I copy the output?+
Yes. Use the Copy output button.
Client-side only?+
Yes. No server processing.
Is this free?+
Yes.