Rail Fence Cipher

Write text in zig-zag rails and read row-by-row.

Rails and zigzag path

Rails

Rail Fence writes letters in a zigzag and then reads them off row by row. Minimum practical value is 2 rails.

Type: Transposition cipher Rails: 3 Cycle length: 4 Path preview: 1-2-3-2-1-2-3-2 Encrypt: write zigzag, read rows

Options

Preserve case

Keep punctuation & numbers

Remove whitespace

Group letters

Encryption writes letters down and up across the rails. Decryption reconstructs that same zigzag path and fills the letters back in correctly.

Output stats

Mode: Encrypt Rails: 3 Letters processed: 0 Input chars: 0 Output chars: 0 Blocks: 0

Classic example: plaintext WEAREDISCOVEREDFLEEATONCE with 3 rails gives WECRLTEERDSOEEFEAOCAIVDEN. Turning on Group letters formats the result into uppercase-only blocks.

Input

Output

Using This Tool: Guide & Notes Show guide

Rail Fence writes text in a zig-zag path across rails, then reads the rows to produce ciphertext.

How to use it

Choose the number of rails.
Paste the plaintext or ciphertext.
Use Encrypt to write the zig-zag and read rows, or Decrypt to reconstruct the path.
Check the rail preview to understand the rearrangement.

Options and settings

Rail count changes the height and rhythm of the zig-zag pattern.
Preserve spacing controls whether spaces remain part of the visible output.
Grouping creates classical-looking ciphertext blocks.
Reset defaults returns to the standard simple demonstration settings.

Notes

Rail Fence is a transposition cipher: letters are moved, not replaced.
Very low rail counts are especially easy to recognise.