Sub Cipher
Run Silent, run deep

Available for Macintosh
Intel or Apple Silicon, MacOS 10.12 or newer

Available for iPhone, iPad
iOS/iPadOS 12 or newer

Overview Pricing & Download Features What's New Screen Shots Help/FAQ Future Contact

Overview: What is "Sub Cipher"?

Sub Cipher is an easy-to-use Encoder/Decoder app, which can encode or decode "simple substitution ciphers."

It works on the "Caesar" and "Atbash" style cipher methods, which are simple offset-alphabet ciphers. The well-known "Rot13" cipher is one of these.

Simply type or copy-paste your encoded or decoded text to and from e-mail, messages, social media, and it is immediately converted for you. Up to 2,000 characters can be converted at a time.

You can also capture the settings you have dialed in (as lines of text) to save in another document. This can be useful if you are publishing a newsletter or book of ciphers, and want to keep the settings you used with each cipher along with the cipher itself.

Caveat Emptor: These ancient styles of ciphers are very simple and easy to decode! This is simply a fun utility, and is not intended for serious "secret message" work.


Pricing & Download

Macintosh Software

iPhone/iPad Software


Click below to download from the App Store:


Click below to download from the App Store:



  • Easy to use. Type into the plain-text or the cypher-text box, and the converted text is immediately displayed.
  • Easy to transfer. You can select all the converted text and paste it into any other text document.
  • Easy to adjust. Any substitution offset, forward or reverse can be dialed in.
  • Easy to save. The settings you dial in can also be saved as text for your notes.


What's New in This Version

1.0.3, September 2022

  • Increased text entry font size a bit for easier reading.
  • Crisper user interface on all devices.
  • Mac: Added animated "Copied" note when copying settings to clipboard.
  • Better Intro Help Screens.

1.0.0, September 2021

First release, it is ALL new!


Show Me More...


FAQ & Tips

FAQ: Here are some common questions/answers...

Read the Software Privacy Policy Here


What is next?

Originally, I quickly built Sub Cipher to help me create some simple cryptogram puzzles for a book I published. After that, I polished it up for everyone else to use too. So now it is time to ask, "What new things would you like to see next?"

After you enjoy the software, feel free to send me an e-mail and suggest a new feature you might like it to have. Although I cannot promise answering all e-mails or getting all the requests done, I would love to hear what you want, and will add yours to my "to-do" list to work on.

Here are some ideas that are already bobbing on the surface of possibility:

Also, if you have a moment, please rate/review the app in the app store. It lets me and others know how useful this is.


Contact Me

If you have more questions or wish to send me feedback:

Contact Me

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