CWS File

What are CWS files and how to open them

Are you having problems opening a CWS 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 CWS files.

What is a CWS file?

A .CWS file is a Combustion WorkSpace Project file.

A Combustion WorkSpace Project format is a native project file used by Autodesk's Combustion software, a tool for compositing, painting, and arranging visual effects and video footage. It stores a workspace containing video/image sequences ("footage"), operators (such as paint, composite, and effects nodes), layer structure, timelines, camera paths and animation data. These enable users to build visual effects projects by arranging and modifying visual assets over time.

Combustion WorkSpace Project files are created when starting a project in Combustion or exported from other tools like MatchMover or 3ds Max via their "Output to Combustion" or "Export to Combustion Workspace" options. When a scene is rendered with one or more Render Elements and the Output to Combustion is enabled, a workspace file is generated containing references to those elements, along with any camera data, animations, and links to image or video sources. Workspaces can also be imported or merged into existing projects in Combustion to combine operator trees or layer branches.

The Combustion map feature in 3ds Max can create or reference these workspace files so that a Combustion project acts as a material map in 3ds Max. These workspaces can be edited via Combustion, or used as live-updating maps where changes in Combustion affect the material appearance in 3ds Max. Only Combustion version 2.1 and later workspace files are supported in this way.

Some technical identifiers: files begin with the ASCII characters CWS (hex 43 57 53), which also is their signature. In addition to footage sources and operator data, workspace files include structures for camera or helper paths, field of view animation channels, video/image links, and video format metadata.

How to open CWS files

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

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

Last updated: September 21, 2026

Various apps that use files with this extension

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

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