A Zipx file (.zipx) is a Zip file created with one or more advanced compression methods available in WinZip. Using Best method compression to create Zipx files, WinZip will create its smallest Zip files. Best method allows WinZip to choose a compression method for each file type, which will usually provide the best result.
The .zipx extension makes it easier to share highly compressed files with others by making it clear that the file was created using an advanced compression method.
The .zipx extension quickly and easily conveys that WinZip 12.1 or later (or another compatible compression utility) will be required to open the file. The advanced compression methods used in Zipx files are extensions to the original, open source Zip file format. The particular ones available in WinZip are:
*Jpeg and WavPack cannot be selected. WinZip applies them with the correct file types when you use Best method compression.
Of course you can still choose to create the most compatible .zip files, using Legacy Zip 2.0 compression. This can be done by changing the compression method on a case by case basis (if you are using the context menu) or it can be done by changing the default compression method.
If you have any questions, please email Technical Support.
Default compression - What it is, how to change it
What is the difference between "Legacy" and "Best method" compression?
Using Jpeg compression in WinZip