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Penrose Cryptogram Solver

This is BETA Software

This handy applet is a Java implementation of a Windows application written by Kite as a refinement of an old DOS application used by Dart. It allows you to easily track your letter replacements as you work through a cryptogram.

Java by Sun Microsystems

This application requires Sun™ Java™ 1.4.2 for your browser. Look for “Java Software Download” at for an upgrade. This is also called a “Java 2 platform.” Sun is currently shipping Java 1.5.x, so hopefully this application will run on most computers including those not on the “bleeding edge.” Mozilla and IE can tell you about your browser's capability if you put “about:plugins” into the address bar.


  1. Type your cryptogram into the upper Cypher window.
  2. Press the [Clear] button if you've been doing any other cryptograms.
  3. Type letters into the lower Cypher box, and matching letters into Plain Text box.
  4. When you have the matched each Cypher letter to a Plain Text letter, you can press the [Exchange] button.
  5. The three alphabets show you how the letters swap out. An upper alphabet letter is in the Cypher text and the lower alphabet is always the Plain Text letter that matches the letter above. This is true whether you are working in the top pair, or the lower pair of alphabets.
  6. Tip: Java uses [Ctrl-Tab] to move out of Edit controls (Mac=[Cmd-Tab]).

The Rules page is reserved for future features that are not yet implemented in this version. They may never be since this version follows all the rules for NPL cryptograms.

This application runs in browsers tested on:

If you have any problems, contact

Future Features