CDZ File

What are CDZ files and how to open them

Are you having problems opening a CDZ 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 CDZ files.

What is a CDZ file?

A .CDZ file is a PSX Compressed CD Image file.

PSX Compressed CD Image format stores complete images of PlayStation discs in a space-saving compressed form. It is created by the pSX emulator (by ePSXe Software S.L) to replace or supplement uncompressed BIN/CUE or CCD/CUE disc image files. Its purpose is to reduce the storage size of disc images while preserving all necessary data for use in emulation.

Conversion to this format is done using a tool called cdztool provided with pSX. The utility takes standard uncompressed disc image files (.bin/.cue or .ccd/.cue) and compresses them into this format, and can also reverse the process, restoring the full image. Emulation software that supports this format reads it by decompressing during runtime so the disc image behaves as though it were uncompressed.

Its internal structure begins with a fixed header signature: the first four bytes are 43 44 5A 01 (ASCII "CDZ" followed by a version byte 01). At offset 16 bytes there is another identifier 5A 4C 49 42 ("ZLIB") indicating that standard zlib compression is used.

How to open CDZ files

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

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

Last updated: August 31, 2026

Various apps that use files with this extension

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

Help us help others

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