Caesar cipher
The cipher that started them all.
Where it came from
The Caesar cipher is attributed to Julius Caesar, who (per Suetonius) shifted letters by three to keep military messages private. It is arguably the first documented encryption in the West.
It survived two millennia as a teaching example of substitution ciphers — and as a children's puzzle. Nobody has considered it secure since roughly the fall of Rome.
How it works
Each letter moves a fixed number of places down the alphabet: with shift 3, A→D, B→E. Non-letters pass through. UWC lets you pick any shift, not just 3.
It is broken by trying all 25 shifts (brute force is instant) or by frequency analysis. Fun, historical, and cryptographically useless — exactly as intended here.
Apply Caesar cipher
Shift text by any amount — encode or decode, right in your browser.