Decoder++ is an extensible application designed for penetration testers, software developers, and anyone in between looking to effortlessly decode and encode data across various formats. It includes a wide range of preinstalled scripts and codecs, smart decoding and format identification, and supports both graphical user interface (GUI) and command-line interface (CLI) operations.

Get up and running with Decoder++ in just a few steps:

# Install using pip (latest:qt6)
pip3 install decoder-plus-plus[qt6]

# Or, for a qt5 backport:
pip3 install decoder-plus-plus[qt5]

# To leverage all features and plugins:
pip3 install decoder-plus-plus[extras]

For a detailed installation guide, including platform-specific instructions, see the Installation Guide.

This section provides an overview about the individual ways of interacting with Decoder++. For additional usage information check out the Advanced Usage section.

The graphical user interface provides two distinct interaction modes: a main-window-mode and a dialog-mode.

While the main-window-mode supports tabbing, the dialog-mode has the ability to return the transformed content to stdout ready for further processing. As a result Decoder++ can enhance other tools/scripts by providing a graphical user interface for flexible transformation of any input.

While Decoder++ processes the entire input text by default, it allows for selective data transformation as well. To transform only a specific portion of your text, simply highlight the necessary text segment in the input field and then apply the desired codec.

In addition to the graphical user interface Decoder++ also provides a command line interface:

$ dpp -e base64 -h sha1 "Hello, world!"
e52d74c6d046c390345ae4343406b99587f2af0d

Decoder++ allows you to choose from a variety of codecs and scripts:

• Encode/Decode:
  • Base16, Base32, Base45, Base64, Base64 (URL-safe)
  • Binary, Gzip, Hex, Html, JWT, HTTP64
  • Octal, Url, Url+, Zlib
• Hashing:
  • Adler-32, Apache-Md5, CRC32, FreeBSD-NT
  • Keccak224, Keccak256, Keccak384, Keccak512
  • LM, Md2, Md4, Md5, NT, PHPass
  • RipeMd160, Sha1, Sha3 224, Sha3 256, Sha3 384, Sha3 512
  • Sha224, Sha256, Sha348, Sha512, Sun Md5
• Scripts:
  • Caesar, CSS-Minify, Custom Code, Extract URLs, Filter-Lines
  • Identify File Format, Identify Hash Format, JS-Beautifier, JS-to-XML, JQ
  • JSONify, JSONPath, HTML-Beautifier
  • Little/Big-Endian Transform, Reformat Text, Remove Newlines, Remove Whitespaces
  • Search and Replace, Split and Rejoin, Unescape/Escape String, XPath

In cases where you require a bit more flexibility Decoder++ allows you to process your data with custom scripts by using the Custom Code script:

This section provides additional information about how the command line interface can be used.

The commandline interface gives easy access to all available codecs.

To list them the -l argument can be used. To narrow down the search the -l argument accepts additional parameters which work as filter:

$ dpp -l base enc

Codec                 Type
-----                 ----
base16                encoder
base32                encoder
base64                encoder

Decoder++ distinguishes between encoders, decoders, hashers and scripts. Like the graphical user interface the command line interface allows the usage of multiple codecs in a row:

$ dpp "H4sIAAXmeVsC//NIzcnJ11Eozy/KSVEEAObG5usNAAAA" -d base64 -d gzip
Hello, world!

While encoders, decoders and hashers can be used right away, some scripts may require additional configuration. To show all available options of a specific script add the help parameter:

$ dpp "Hello, world!" -s split_and_rejoin help

Split & Rejoin
==============

             Name  Value  Group            Required  Description
             ----  -----  -----            --------  -----------
   split_by_chars         split_behaviour  yes       the chars used at which to split the text
  split_by_length  0      split_behaviour  yes       the length used at which to split the text
rejoin_with_chars                          yes       the chars used to join the splitted text

To configure a specific script the individual options need to be supplied as name-value pairs (e.g. search_term="Hello"):

$ dpp "Hello, world!" -s search_and_replace search_term="Hello" replace_term="Hey"
Hey, world!

Feel free to open a new ticket for requesting features or reporting bugs. Also don't hesitate to issue a pull-request for new features/plugins. More information regarding Decoder++ development can be found in the Development Guide.

Thanks to

• Tim Menapace (RIPEMD160, KECCAK256)
• Robin Krumnow (ROT13)

When starting Decoder++ in Mac OS signals are not working.

This might happen when PyQt6 is installed using homebrew.

When starting Decoder++ in CygWin an error occurs:

  ModuleNotFoundError: No module named 'PyQt6'

This might happen even if PyQt6 is installed using pip. Currently there is no fix for that. Instead it is recommended to start Decoder++ using the Windows command line.

When starting Decoder++ the error No module named 'PyQt6.sig' is displayed on the console. This may happen when there are competing versions of PyQt6 installed. Reinstalling PyQt6 should fix this error.

$ sudo pip3 uninstall PyQt6
$ sudo pip3 install PyQt6

At least in Ubuntu 22.04 it might be necessary to install the following packages using apt:

apt install libqt6core6 libqt6network6 libqt6openglwidgets6 libqt6widgets6

In order to run dpp inside a container/virtual machine you may need to install the qt6-qpa-plugins inside the container/virtual machine and configure the QT_QPA_PLATFORM_PLUGIN_PATH accordingly:

apt install qt6-qpa-plugins
export QT_QPA_PLATFORM_PLUGIN_PATH=/usr/lib/x86_64-linux-gnu/qt6/plugins/platforms/

See the Docker build and run scripts for more information regarding how to build and run a Decoder++ Docker container.

• PortSwigger's Burp Decoder

• QtPy / PyQt5 / PyQt6
• QtAwesome