Web app and framework offering modular conversion, encoding and encryption
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Web app and framework offering modular conversion, encoding and encryption. Translations are done client side without any server interaction — cryptii.com

Getting started

Several quick start options are available:

  • Use the latest live version or download the latest release.
  • Clone the repo: git clone git@github.com:cryptii/cryptii.git
  • Install the node version specified in .nvmrc.
  • Run npm install to install the dependencies.
  • Run npm run-script build to build into the dist/ folder.
  • Run npm run-script test to test the source code.
  • Run npm run-script watch to watch for changes.


This framework and web app tries to reflect a wide variety of ciphers, formats, algorithms and methods (called 'bricks') while keeping them easily combinable. There are two categories of bricks: encoders and viewers.


Encoders manipulate content by encoding or decoding it in a specific way and using specific settings.

Name Category Description
text-transform Transform Transforming character case and arrangement
numeral-system Transform Translates numerals between systems
bitwise-operation Transform Bitwise operations (NOT, AND, OR, …)
morse-code Alphabets Morse code (English)
spelling-alphabet Alphabets Several spelling alphabets
rot13 Simple Substitution ROT13 incl. variants ROT5, ROT18 & ROT47
affine-cipher Simple Substitution Affine Cipher
caesar-cipher Simple Substitution Caesar cipher
atbash Simple Substitution Atbash using latin or hebrew alphabet
vigenere-cipher Simple Substitution Vigenère cipher incl. Beaufort cipher variants
enigma Simple Substitution Enigma machine incl. 13 models
base64 Encoding Base64 incl. variants base64url, …
ascii85 Encoding Ascii85 / Base85 incl. variant Z85
unicode-code-points Encoding Encoding to Unicode code points in given format
url-encoding Encoding URL encoding / Percent-encoding
integer Encoding Translates between bytes and integers
block-cipher Modern cryptography Block ciphers incl. AES
hash Modern cryptography Creating a message digest
hmac Modern cryptography Creating a Hash-based message authentication code

Example usage:

const bricks = cryptii.BrickFactory.getInstance()
const encoder = bricks.create('rot13')
encoder.setSettingValue('variant', 'rot47')
const result = encoder.encode('Hello World') // returns a Chain object
result.getString() // returns 'w6==@ (@C=5'


Viewers allow users to view and edit content in a specific way or format.

Name Category Description
text View Viewing and editing in plain text
bytes View Viewing and editing bytes


Chain objects encapsulate the actual content used and returned by encoders and viewers. This content can either be a string, an array of Unicode code points or a Uint8Array of bytes.

Chains are immutable. You define its content by passing one of these representations as first argument to the constructor.

const a = new cryptii.Chain('🦊🚀')
const b = new cryptii.Chain([129418, 128640])
const c = new cryptii.Chain(new Uint8Array([240, 159, 166, 138, 240, 159, 154, 128]))
cryptii.Chain.isEqual(a, b, c) // returns true

The object handles the translation between these representations lazily for you. You can access any of these through getter and additional convenience methods.

const string = chain.getString()
const codePoints = chain.getCodePoints()
const bytes = chain.getBytes()


See the Releases section of the GitHub repository for changelogs for each release version of cryptii.