Columnar Transposition Cipher

Write letters into keyword columns and read them back in alphabetical key order.

Keyword

Keyword (A-Z letters only; duplicate letters are allowed and tied left-to-right)

Columns are read in alphabetical key order. Duplicate key letters keep their original left-to-right order.

Normalised key: ZEBRAS Columns: 6 Ranks: 6, 3, 2, 4, 1, 5 Read order: 5 → 3 → 2 → 4 → 6 → 1 Column 5 (A) is read first Column 1 (Z) is read last

Options

Preserve case

Keep punctuation & numbers

Remove whitespace

Group letters

This tool transposes letters only. With punctuation kept on, non-letters stay where they are and only the letters are rearranged.

Output status

Mode: Encrypt Effective key: ZEBRAS Letters processed: 0 Input chars: 0 Output chars: 0 Rows: 0 Columns: 0 Blocks: 0

Classic example: plaintext WEAREDISCOVEREDFLEEATONCE with key ZEBRAS gives EVLNA CDTES EAROF ODEEC WIREE when Group letters is on. No padding is added; short final columns are handled correctly during decryption.

Input text

Output text

Using This Tool: Guide & Notes Show guide

Columnar transposition writes text under a keyword, then reads columns in the order determined by that keyword.

How to use it

Enter the keyword that sets the column order.
Choose Encrypt or Decrypt.
Paste the text into the input box.
Use the grid display to check how rows and columns are filled and read.

Options and settings

Keyword length controls the number of columns.
Duplicate keyword letters need a consistent ordering rule.
Padding fills incomplete final rows when needed.
Grouping formats the final output without changing the transposition.

Notes

This cipher rearranges letters rather than substituting them.
Wrong keyword length or ordering gives a scrambled decryption.

Columnar Transposition Cipher guide coming soon

The matching article is not published yet. This tool is ready now, and the guide can be added through the shared article template when it is written.

Guide coming soon

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A note from the team

We build these tools because we love cryptography, encoding, and making difficult ideas easier to explore. If they've helped you, even a small coffee means the world to the project. Thank you!

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