dec 

Opening DEC files

Have a problem opening a .DEC file? We collect information about file formats and can explain what DEC files are. Additionally we recommend software suitable for opening or converting such files.

What is the .DEC file type?

The main association of the .dec extension goes together with the Magic Online Card Deck (.dec) file type. Magic Online is an electronic, online version of the well-known board card-based game Magic: The Gathering (MTG) by Wizards of the Coast LLC. With its intricate rules, MTG involves decks of cards that players can use to cast magic, engage in combat, move, and perform other in-game actions.

A .dec file is a plaintext file that uses a very simple syntax to describe cards that make up an MTG player's deck. Any .dec file can be created, opened, or modified in a text editor. There are also multiple mobile/desktop tools that can generate custom .dec files to be used with Magic Online.



Magic Online V3 (Version 3) introduced a newer, XML-based deck format (.dek). Older .dec files can be automatically converted to .dek, once they are opened and re-saved.


Another association of the .dec extension is bound up with the POM-QM for Windows Decision Conditions (DEC) file type. Standing for 'Production and Operations Management, Quantitative Methods,' POM-QM for Windows is a paid Microsoft Windows application by H.Weiss (Pearson Education), since long widely used in educational institutions for teaching POM and QM.

In the scope of POM-QM for Windows, a .dec file is a short plaintext list of decision conditions that are used to solve statistical, logistical, and other problems in POM-QM. Any .dec file can be easily opened and modified in a text editor.


Additionally, the .dec extension is associated with the EDK II Declaration (DEC) file format and type. Intel's EDK II (EFI Developer Kit) is a software framework to develop UEFI (Unified Extensible Firmware Interface) modules. A .dec file is a text-based document that contains INI-like declaration statements for a binary EDK II package. DEC files are meant to be viewed and modified by system and software engineers.


LeCroy CATC protocol analyzers use the .dec extension to identify text-based decoder script files (.dec) written in the CATC Scripting Language (SCL) and used to decode communication transactions. All .dec scripts placed into the "/scripts" directory are loaded and executed automatically.


In the area of scientific research, the .dec extension gets used by the ProMass mass-spectrometry software (Novatia, LLC) to denote the ProMass Deconvolution Results (DEC) file type/format. Generated in ProMass, deconvoluted spectra (.dec) can be opened with the ProMass DecView tool (Microsoft Windows).


In computer-aided manufacturing, the .dec extension is employed by the Autodesk Fabrication CAM-Duct application to denote output files that are generated to control decoiler machines. Such .dec files are saved into a specified directory, to be uploaded into a decoiler. Depending upon machine makes and models, .dec files are saved in different formats.


In dendrology, the .dec extension represents the CDendro Decadal File (DEC), an older format and file type that was used with earlier versions of the CDendro dendrological research application. In a .dec file, text-based tree year-ring data are stored in a special format. Current CDendro versions switched to the newer Tucson decadal format (.rwl), while still supporting .dec files.


Lastly, the .dec extension can be assigned to any decoded or decrypted files generated by various decoding/decrypting tools. Here, the .dec suffix points out that a file has been restored to its original, un-encoded state and can be opened normally.

Software to open or convert DEC files

You can open DEC files with the following programs: 

Popular formats