CPJ File

What are CPJ files and how to open them

Are you having problems opening a CPJ 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 CPJ files.

What is a CPJ file?

A .CPJ file is a WinOnCD Project file.

WinOnCD Project files store all the settings, layout, track list and burn options for a CD project in WinOnCD (also called CPJ project by Sonic Solutions / Roxio). They are used whenever a user has assembled tracks (audio, data, video), set disc parameters (type, finalize mode, number of copies, UPC/EAN codes, etc.), chosen track names, and arranged the layout; the program saves all this in a single file so the project can be reopened later without having to rebuild everything.

These files are created and read exclusively by WinOnCD (CeQuadrat's disc-burning software, later acquired by Sonic Solutions and Roxio). When a project is "saved," WinOnCD writes this CPJ project file. When the user "opens" a project, WinOnCD loads it to restore the exact same configuration of tracks, disc formatting options, project metadata, copy count, finalization or session state.

Internally, the file begins with a recognizable ASCII header at the very start: the signature "[WinOnCDProject]\r\n". The content includes plain-text keywords or fields such as LAYOUT_TRACKNAMES, WINONCD OPTIONS, FINALIZE MODE, IMAGE FOLDER, DISCTYPE, DISCTIME, COPIES, UPCEAN, PLUGIN, plus entries for individual tracks (TRACK1, JOB1). These all describe project-wide settings or individual track names and properties.

How to open CPJ files

Important: Different programs may use files with the CPJ file extension for different purposes, so unless you are sure which format your CPJ 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 CPJ openers which you will find listed below.

Last updated: September 2, 2026

Various apps that use files with this extension

These apps are known to open certain types of CPJ files. Remember, different programs may use CPJ 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 CPJ file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.