Online Tool Store
Enigma Machine Simulator
Encrypt and decrypt messages using a historically accurate Enigma I simulation — real rotor wirings, reflector, and plugboard, in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Only letters A-Z are encrypted — spaces and other characters are passed through unchanged.
Running the output back through with the same starting settings decrypts it — that reversibility is the whole point of the real Enigma's design.
How the Enigma machine simulator works
- Type a message and choose which three rotors to use, in which order.
- Set each rotor's starting position, and optionally add plugboard letter-swap pairs.
- The output updates instantly, simulating the same electrical path a real Enigma machine would take for each letter.
How the encryption actually works
Each keystroke first passes through the plugboard, then through three rotors (each rotor substituting one letter for another based on its internal wiring), bounces off a reflector, and travels back through the same three rotors in reverse — and critically, at least one rotor advances one position before every single letter, so the same input letter almost never produces the same output letter twice in a row.
FAQ
Is this a real, historically accurate Enigma simulation?
It reproduces the real Enigma I rotor wirings (rotors I-V), notch positions, and Reflector B used by the historical machine, along with a plugboard — so encrypting and decrypting behaves the same way the wartime machine did, for educational purposes.
How do I decrypt a message I encrypted?
Set the rotors, starting positions, and plugboard exactly as they were when you encrypted the message, then paste the encrypted output back into the message field — Enigma's design makes encryption and decryption the same operation, run with identical settings.
What does the plugboard do?
It swaps pairs of letters before and after the rotor scrambling, adding another layer of substitution. Historically it was one of the biggest contributors to the cipher's complexity — enter pairs like "AB CD" to swap A↔B and C↔D.
Is my message sent anywhere?
No. The entire simulation runs in your browser using the same rotor logic as the real machine — nothing is sent to Online Tool Store or any other server.
How we compare
| Feature | Online Tool Store | cryptii.com Enigma simulator | A physical Enigma replica |
|---|---|---|---|
| Free, no install | ✓ | ✓ | Expensive collectible |
| Historically accurate rotor wirings | ✓ | ✓ | ✓ |
| Message never sent anywhere | ✓ | Not stated | ✓ |
For a genuine, playable Enigma simulation without buying a collectible replica, the Online Tool Store Enigma Machine Simulator reproduces the real cipher logic in your browser.