Rail Fence Cipher
Encrypt and decrypt text with the rail fence transposition cipher using a chosen number of rails. A classic zigzag cipher.
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Encrypt and decrypt text with the rail fence zigzag transposition cipher.
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Encrypt with the rail fence cipher
The rail fence cipher is a transposition cipher that rearranges the letters of a message rather than substituting them. The text is written in a zigzag pattern across a chosen number of rails, or rows, and then read off row by row to produce the ciphertext. With three rails, the message HELLOWORLD becomes HOLELWRDLO. Decryption reconstructs the zigzag pattern and reads the letters back in their original order.
The number of rails is the key, and more rails produce a more thorough scramble for longer messages.
A classic transposition
Because it only reorders letters, the rail fence cipher preserves the letter frequencies of the original, which makes it weak against analysis, but it is a wonderful introduction to the idea of transposition ciphers. It appears often in puzzles, escape rooms and cryptography lessons. The zigzag pattern is easy to draw by hand, which historically made it practical for quick field use.
Like other classical ciphers, it offers no real security and must not protect sensitive data. It works on the characters as given, including spaces. All processing happens locally in your browser.
Privacy and usage
Because the rail fence cipher runs entirely in your browser, nothing you enter is uploaded or stored, so you can use it with sensitive values safely. The output is generated locally and never transmitted, and you can run the tool as many times as you need for free.
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Frequently Asked Questions
How does the rail fence cipher work?
The message is written in a zigzag across a set number of rails and then read off row by row, rearranging the letters without changing them.
What is the key?
The number of rails. More rails create a more thorough rearrangement, and the recipient needs the same number to decrypt.
Is it a substitution cipher?
No. It is a transposition cipher: it reorders the existing letters rather than replacing them with different ones.
Is the rail fence cipher secure?
No. It preserves letter frequencies and is easily broken, so it is for learning and puzzles rather than real security.
Privacy & Security
Everything runs in your browser; nothing is uploaded.
How to Use
Enter text and the number of rails, then encrypt or decrypt.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.
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SecurityMeasure password strength by entropy and pattern analysis rather than character-class rules. Checked entirely in your browser.
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SecurityGenerate MD5, SHA-1, SHA-256 and SHA-512 hashes in your browser. Compare checksums and verify file integrity with nothing uploaded to a server.