Rail Fence Cipher
Encrypt and decrypt messages using the Rail Fence (zigzag) transposition cipher — choose the number of rails and get the result with working shown.
What Does This Tool Do?
The Rail Fence cipher writes text in a zigzag pattern across a set number of rails, then reads off row by row. A transposition cipher — letters are rearranged rather than substituted.
Key Features
Zigzag Pattern
Writes diagonally across chosen number of rails.
Encrypt & Decrypt
Both directions with the same rail count.
Working Shown
Understand the rail pattern.
Copy Result
One-click copy.
How to Use
- Enter the message to encrypt or decrypt.
- Set the number of rails (default 3).
- Click Encrypt or Decrypt.
Frequently Asked Questions
How does the Rail Fence cipher work?▾
Write the message diagonally across N rails in a zigzag. Then read off each rail left-to-right. Example with 3 rails: "HELLO" → H on rail 0, E on rail 1, L on rail 2, L on rail 1, O on rail 0.
Is it a substitution or transposition cipher?▾
Transposition — the letters stay the same but their positions are rearranged. No letter is replaced by another.
How do I decrypt?▾
Enter the ciphertext, set the same number of rails, and click Decrypt. The tool reconstructs the zigzag positions and reads off the original order.