Pigpen Cipher
Turn letters into pigpen (Freemason) symbols, with a full chart to decode.
How to Use Pigpen Cipher
- Type the text you want to encode into the input box.
- Each letter is drawn as its pigpen symbol below, in order.
- To decode a pigpen message, match each symbol against the A-Z chart on this page.
- Pigpen is a graphical substitution cipher — letters become shapes from a grid and an X.
Examples
How it encodes — input:
MEET
Output:
Four pigpen symbols (see the live output and chart)
Grid vs X letters — input:
A-R use tic-tac-toe cells
Output:
S-Z use the X shapes
Center square — input:
E
Output:
A full square (all four sides)
The Pigpen Symbol Chart, Explained
Pigpen has no random key to memorize — every symbol is just the lines that surround a letter's position in one of four shapes. Learn the four shapes and you can read any pigpen message by hand:
Grid 1 — A to I (no dot)
A 3×3 tic-tac-toe grid. Reading left to right, top to bottom: A B C / D E F / G H I. Each letter's symbol is the walls of its cell — a corner (A, C, G, I) has two lines, an edge (B, D, F, H) has three, and the centre E is a full square.
Grid 2 — J to R (with a dot)
The same 3×3 grid holds J K L / M N O / P Q R, drawn with the identical wall shapes but with a single dot inside. The dot is the only thing separating, say, A from J or E from N.
X 1 — S to V (no dot)
An X splits into four wedges: S points right (>), T points up (∧), U points left (<), V points down (∨). Each letter is one wedge, no dot.
X 2 — W to Z (with a dot)
A second X holds W X Y Z as the same four wedges, each carrying a dot. So a wedge with a dot is always one of W–Z.
Live symbols for every letter appear in the tool output above; use this breakdown to decode a message with pencil and paper.
Worked Example: Encoding “MEET”
Encode one letter at a time by finding its shape and dot:
- M is in Grid 2 (J–R), middle-left cell. Its walls are top, bottom and right, with the left side open — an open-left shape — plus a dot.
- E is the centre of Grid 1 (A–I), so it is a full square with all four sides and no dot.
- E again: the same full square. In pigpen a repeated letter always draws the identical symbol.
- T is in X 1 (S–V) and points up (∧), an upward wedge with no dot.
Type MEET into the tool above to see these four symbols drawn out, then try your own word. Because two of the letters repeat, this word is a quick way to see how a repeated letter gives away a pattern — one reason pigpen is easy to crack.
A Short History of the Pigpen Cipher
The pigpen cipher is best known as the Freemason's cipher (also the masonic cipher): Freemasons used it in the 18th century to keep their records and correspondence private. The grid-and-dot design made it quick to write by hand and easy to teach to members.
It later saw real-world use in the field — Confederate soldiers used pigpen during the American Civil War — and it has appeared in puzzles, games and treasure hunts ever since. The nickname “pigpen” comes from the way the letters sit in little pens formed by the grid.
For all its history, pigpen is a simple substitution cipher: the letter-to-symbol mapping is fixed and public. Anyone with the chart decodes it instantly, and even without the chart it yields to the same frequency analysis that breaks a Caesar or Atbash cipher. Treat it as a fun, historical puzzle — not real security.
Frequently Asked Questions
How does the pigpen grid work?
Two 3×3 grids and two X shapes hold the 26 letters: A–I in a plain grid, J–R in a dotted grid, S–V in a plain X, and W–Z in a dotted X. Each symbol is the lines around a letter's position, plus a dot if it comes from a dotted set.
Is the pigpen cipher secure?
No. It is a fixed substitution, so the chart decodes it instantly and frequency analysis breaks it without the chart. It is ideal for puzzles and learning, not for protecting real secrets.
Why is it called the Freemason's cipher?
Freemasons used it in the 18th century to keep records private, so it is also known as the Freemason's or masonic cipher.
How do I decode a pigpen message by hand?
For each symbol, decide whether it is a grid shape or an X wedge, then check for a dot: grid without a dot is A–I, grid with a dot is J–R, X without a dot is S–V, X with a dot is W–Z. The chart above maps every position.
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