Rail Fence Cipher

How to use

1. 1Choose Encode to scramble a message or Decode to recover one.
2. 2Type or paste your text into the input box.
3. 3Set the number of rails, and make sure the sender and receiver use the same count.
4. 4Optionally add a start offset or turn on letters-only mode to match a specific variant.
5. 5Read the result, watch the fence diagram, and copy the output or send it to the other mode.

About this tool

Rail Fence Cipher encodes and decodes the classic zigzag transposition cipher entirely in your browser. The cipher works by writing your message diagonally down and up across a fixed number of horizontal rails, then reading the letters off one rail at a time to produce the ciphertext. To decode, the tool rebuilds the same zigzag path, refills the rails from the cipher text in order, and reads the message back along the path. You can set the number of rails from 2 to 12, add an optional starting offset for textbook variants that begin partway through the zigzag, and switch on letters-only mode to strip spaces and punctuation the way the cipher is usually taught. A live fence diagram draws exactly where every character lands on the zigzag, which makes it easy to follow the transformation and check your work by hand. Because it is a transposition cipher, it rearranges your letters rather than substituting them, so it pairs naturally with substitution ciphers like Caesar, Vigenere, and Atbash. It is handy for puzzle hunts, capture-the-flag challenges, escape rooms, geocaching mystery caches, and classwork on classical cryptography. The rail fence offers no real security against modern attacks, so treat it as a learning and puzzle tool rather than protection for sensitive data. Everything runs locally, so the text you type is never uploaded.

Free to use. Works in your browser. No signup, no login.