Get Decrypt0r

Put this puzzle solver on your web site.

Click the "Get code" button for more info.

What is it

Decrypt0r is an online code-breaking application. It cracks codes using sophisticated dictionary attacks and letter frequency cryptanalysis in the browser. Decrypt0r breaks most simple ciphers like those published in newspapers. It cracks Caesar cyphers, ROT-X, block ciphers, XOR, and various algorithmic, equation group ciphers like the ones created by our Bit Rot cryptogram puzzle maker. A sample cipher is included. It also checks spelling.


  1. Paste text or code in the box
  2. Click
  3. Try any of the ranked suggestions.
  4. Click suggestion again to undo.

Create new codes using the Bit Rot translator, and break them. Try other formulas, such as c^3. Notice how Decrypt0r's letter frequency analysis can decode Caesar ciphers fairly easily. That's the point of this exercise.

Using the panel -->

Type different letters into the panel and the text is automatically updated. Try typing different letters in the boxes until the text becomes readable, or until the spell check finds agreeable suggestions in the dictionary.

Alternate letter frequency tables

The default English letter frequencies may be easily changed by spell checking different texts. Simply paste some text (in the target language or dialect) into the application and train it by clicking the button twice, so the letters on both sides of the = signs match up. Then Paste a coded message in the box, , or like before. Letter frequencies can vary somewhat between different authors and subject matter. Thus previously-deciphered messages make the best training material. This data has even been used to prove authorship.

Alternative dictionaries

The dictionary is dynamically loaded, so it would be easy to specify another dictionary in the source code. In the future there might be several dictionaries to choose from. Suggestions welcome. ;)

CCBY Copyright © 2016 Henry Kroll III, This web page is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.