Enigma I Simulator

Greek / 4th Beta

Slow III

Middle II

Fast I

Configuration hidden — click Settings to open

Rotors ?

Choose distinct rotors. In Enigma I mode, choose 3 rotors (I–V). In M4 Navy mode, select the 4th Greek rotor (Beta or Gamma) plus 3 rotors (I–VIII). Order shown is left-to-right matching the physical machine.

Greek / 4th

Slow

Middle

Fast

Ring Settings (Ringstellung) ?

Offsets the internal wiring relative to the rotor's outer ring. Populated A–Z automatically.

Greek

Slow

Middle

Fast

Start Position ?

The visible letters on the rotors at the moment you begin typing — your message key.

Greek

Slow

Middle

Fast

Plugboard (Steckerbrett) ?

Swap up to 10 letter pairs before the signal reaches the rotors. Format: space-separated pairs, e.g. "AB CD EF".

No swaps

Reflector (Umkehrwalze) ?

Reflects the signal back through the rotors on a second pass. UKW-B and UKW-C are standard wide reflectors; Thin-B and Thin-C are specialized thin reflectors designed for the naval M4 machine.

Message ?

Only A–Z is encrypted; everything else is ignored. Enigma has no numbers or punctuation.

Output

0 chars

Lampboard

Lights up as each letter is enciphered.

Trace Path 0 steps

The signal's path through plugboard → rotors → reflector → rotors → plugboard.

Type a message to see signal propagation

Input → Plug → R1 → R2 → R3 → Ref → R3′ → R2′ → R1′ → Output

Trace Speed 140 ms

Slow Fast

⚙ Stepping Mechanics

The fast rotor steps on every keypress. When it reaches its notch, the middle rotor also steps. If the middle rotor is at its own notch, it steps again alongside the slow rotor — the famous "double-stepping" anomaly. On the M4 Navy model, rotors VI, VII, and VIII have dual turnover notches (Z and M), while the 4th Greek rotor (Beta/Gamma) remains stationary during typing.