Caesar Cipher — Shift Cipher Tool
Encrypt and decrypt with an adjustable shift slider.
0 Characters
Shift+3
-250+25
Encrypted (shift +3)
Decrypted (shift -3)
The two cards are independent views of your input. To decode, paste the ciphertext above (e.g. "defg" decrypts back to "abcd" at shift 3; "a" wraps around to "x").
About the Caesar Cipher
Two thousand years ago Julius Caesar protected military orders by shifting each letter three places down the alphabet. This tool recreates that cipher with a slider covering every possible shift from -25 to +25, showing the encrypted and decrypted views side by side so you can experiment in both directions at once.
It is a perfect first cipher for classrooms and CTF warm-ups: simple enough to crack by hand, structured enough to teach what a key is. ROT13, by the way, is just a Caesar cipher with the shift locked at 13.
How to use it
- 1Type or paste your message.
- 2Drag the slider to choose a shift between -25 and +25.
- 3Copy the encrypted or decrypted card — both update live.
Frequently asked questions
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