DECK File

What are DECK files and how to open them

Are you having problems opening a DECK file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your DECK files.

What is a DECK file?

DECK files have multiple uses, and CanDo Deck is one of them. Read more about the other uses further down the page.

CanDo Deck

We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

How to open DECK files

Important: Different programs may use files with the DECK file extension for different purposes, so unless you are sure which format your DECK file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested two different DECK openers which you will find listed below.

Last updated: October 22, 2026

All known file formats using extension .DECK

While CanDo Deck is a popular type of DECK-file, we know of 3 different uses of the .DECK file extension. Different software may use files with the same extension for different types of data.

Decker Deck

Decker Deck files store interactive multimedia documents made with the Decker platform, a tool for creating decks composed of "cards" laid out with widgets, scripts, images, sound, and other media. A deck can contain multiple cards; each card can contain interactive elements (widgets) like buttons, fields, sliders, grids, canvases, or custom contraptions. Scripts written in the Lil language respond to events (clicks, view updates, etc.), so decks support hypertext, interactivity, and customizable layout.

Such files are authored by Decker (both its native and Web-Decker versions). They are used to build, share, edit, and present interactive documents: authoring is done through Decker's UI or external tools (like its scripting interface called Lilt), then decks are viewed or interacted with in Decker. Native Decker saves .deck files; Web-Decker can also export "standalone" decks in .html that embed deck data plus runtime.

The file format is UTF-8 text from start to finish, comprising a "payload" section that defines Deck, Cards, Widgets, Scripts, Fonts, Sounds, Modules, and Contraptions. A deck is divided into named chunks like {deck}, {card:ID}, {widgets}, {script:ID}, and ends with {end} where appropriate. Widget definitions include fields such as "type", "size", "pos", "value", "font", "pattern", and script references. Sounds are stored as 8 kHz mono PCM; images use datablocks prefixed with %%IMG…; fonts use FNT…; there are also data blocks for arbitrary data %%DAT… formats.

For technical identification, files start with the ASCII signature {deck} (bytes 0x7B6465636B7D) and include internal keywords like ON CLICK DO, {WIDGETS}, %%IMG2A, BUTTON1, VERSION, {SCRIPT, IMAGE, VALUE, {CARD, {END}, NAME, SIZE, TEXT, TYPE}. These markers help tools recognize the format.

Wiz Solitaire Cards Deck

Wiz Solitaire Cards Deck files store custom "card set" or "deck" definitions used by the Wiz Solitaire game by Simone Tellini. They represent a visual theme or artwork for the deck - that is, the appearance of cards (face, back, sizes, possibly shapes) rather than the rules or layout of the solitaire games themselves. They are created and edited using the Deck Editor tool bundled with Wiz Solitaire on platforms like Windows. These files are read by the game to render cards in-game using the custom graphics and layouts defined.

Typical workflows begin by using the Deck Editor to import image files in formats such as GIF, JPG, BMP, WMF for card faces and backs; deck files then reference those images and define parameters like card sizes and borders. After editing, Wiz Solitaire loads them so players can use these decks in any of the built-in solitaire variants or the custom ones they've configured.

Files in this format begin with a signature or header identifying them as Wiz Solitaire Cards Deck files. Specifically, the first bytes are the ASCII string "WizSolitaireDeck" starting at offset zero.

Various apps that use files with this extension

These apps are known to open certain types of DECK files. Remember, different programs may use DECK files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about DECK file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.