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Simulators

Cipher Tools

KS3

Drag the inner (violet) ring to change the shift, or use the buttons below. Press any letter key to see it highlighted on the wheel.

ABCDEFGHIJKLMNOPQRSTUVWXYZPlaintextABCDEFGHIJKLMNOPQRSTUVWXYZ⟳ drag to rotateCiphertextshift+3
+3
Plaintext (outer)Ciphertext (inner)Key pressedEncrypted letter

Try It

Type letters on your keyboard. They'll be encrypted with shift +3.

Plaintext
type here…
Ciphertext
encrypted text…
Formula
C = (P + 3) mod 26
How to decode: subtract the shift (or add 26 − shift). ROT13 (shift +13) is self-decoding — apply it twice to get back the original.