Casc Storage

(Library and client application)

Casc Storage

Since 2014, Blizzard Entertainment has changed data format in their games from MPQ to CASC (Content Addressable Storage Container). A library that can parse the storages can be downloaded from Github.

Extracting data from Casc Storage

The CascView tool is available for all main Blizzard games:

Download CascView for Windows (32+64 bit) v


Some CASC storages, namely for World of Warcraft do not hold file names. Names are encoded as 64-bit hashes in the storage and accesses as such by the game. For extracting World of Warcraft files, you need to use a listfile. You can download one here. There is a community of people that keep working on it.

What about Overwatch?

Support on Overwatch is in early stage. Based on how I have time and information about how to extract files, I'll add the support there. At the moment, CascLib is only able to extract most files by their encoding key.

What files and directories form a CASC storage?

When browsing the data subdirectory in the game directory, you may notice several files in various subdirectories. There are data files in the "data" subdirectory that contain the files. However, unlike MPQs, the data files are not standalone archives. You need the complete storage directory with several extra files to make CascView open the storage and extract files from it. The following list contains the complete list of files and directories that you need to preserve in order to be able to extract files:

How to open CASC storage with CascView?

When opening a game storage directory, you can either enter the storage at the command line or select "File\Open Storage" in the application UI. To open the storage, you either select a game directory or one of the storage subdirectories (no matter how deep). Examples:

CascView.exe "c:\Games\Diablo III"
CascView.exe "C:\Games\Heroes of the Storm\HeroesData"
CascView.exe "C:\Games\World of Warcraft\Data"
CascView.exe "C:\Games\Overwatch\data\casc\config\66\77"