Sub Cipher - Free

Run Silent, run deep

For Macintosh (macOS 10.12+)

(Intel and Apple Silicon)

For iPhone/iPad (iOS 12.0+)

Overview | What's New | Pricing/Download | Screen Shots | FAQ/Help | Contact Info | SchwanSongs Home Page
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.

Here are the main features:

  • 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

1.0.0, September 2021

First release, it is ALL new!


Sub Cipher is free.

Available for any Macintosh, macOS 10.12 and up

Available for iPhone/iPad, iOS 12 and newer

Screen Shots & Examples

Create and decode secret messages easily.

Slide through different "Simple Substitution" ciphers.

A little extra help is always there.

Easily paste and save your cipher settings as text into different documents.

Copy/paste the converted text in or out.

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:

  • Add the keyword, Vigenère, or other cipher.
  • Allow other alphabets, like "Pigpen/Templar/Masonic", Greek, Runic.

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


Q: I have an entire chapter/poem to encode or decode. Can Sub Cipher handle it?
A: Yes! It can convert 2000 characters total, at a time. If your text is longer than that, you can convert it a paragraph or two at a time.

Q: Where can I find out more about these kinds of ciphers?
A: I would start by
clicking here.

Q: Somebody said you hid some of your music in here... where is it?
A: Simply click/tap on the application icon to hear it.

Privacy Policy

Yes, we have a Privacy Policy. Read it here.

Contact Me Have more questions? Want to send me feedback? Contact me here!