CSO file format description

Many people share .cso files without attaching instructions on how to use it. Yet it isn’t evident for everyone which program a .cso file can be edited, converted or printed with. On this page, we try to provide assistance for handling .cso files.

2 filename extension(s) found in our database.

.cso - CSO Compressed PSP ISO Image

The CSO disk image files are related to ISO Compressor. The CSO file is a CSO Compressed PSP ISO Image. CSO is used to compress dumped Sony PlayStation Portable (PSP) UMD games.

ISO Compressor
Disk Image files
- / -
CSO Compressed PSP ISO Image related extensions:
UltraISO Compressed Image
UltraISO Backup Image
Tiny Core Linux TCZ Image
CloneCD Image Information
MagicISO Multi-Boot Image
Roxio Recordnow! CD Image

.cso - High Level Shader Language Compiled Bytecode

The CSO development files are related to DirectX SDK. The CSO file is a High Level Shader Language Compiled Bytecode. The High-Level Shader Language (HLSL) is a proprietary shading language developed by Microsoft for the Direct3D 9 API to augment the shader assembly language, and went on to become the required shading language for the unified shader model of Direct3D 10 and higher.

DirectX SDK
Development files
- / -
High Level Shader Language Compiled Bytecode related extensions:
µVision Absolute and Executable Object
RemObjects SDK Test Results Data
CoffeeScript Literate Script
Eclipse Modeling Framework GenModel Data
Visual Studio JOOB Object Model Project
Visual Studio GL Shader Data

Naturally, other applications may also use the .cso file extension. Even harmful programs can create .cso files. Be especially cautious with .cso files coming from an unknown source!

Can't open a .cso file?

When you double-click a file to open it, Windows examines the filename extension. If Windows recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When Windows does not recognize a filename extension, you receive the following message:

Windows can't open this file:


To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select one from a list of programs that are installed on your computer.

To avoid this error, you need to set the file association correctly.

The .cso file extension is often given incorrectly!

According to the searches on our site, these misspellings were the most common in the past year:

cco, ceo, co, cos, cs, csi, csk, csl, csp, cxo, dso, fso, sco, so, sso

Is it possible that the filename extension is misspelled?

Similar file extensions in our database:

CHARTrunner Pareto Style
Capture One Settings
Scilab Binary Diagram
ContentServ CS EMMS Include
InterSystems Cache Server Page
Unix Shared Library

Operating systems

DataTypes.net currently supports the following operating systems:

Windows XP/Vista, Windows 7/8/10, Windows 11, CentOS, Debian GNU/Linux, Ubuntu Linux, FreeBSD, macOS, Mac OS X, iOS, Android

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DataTypes.net >> CSO file