At one time, the maximum file size allowed by the Zip file specification was 4 gigabytes. This limit applied both to the uncompressed and compressed sizes of files inside Zip files (.zip or .zipx), and also to the total size of a Zip file itself. In particular, this 4-gigabyte limit applied to WinZip versions 7.0 to 8.1 SR-1.
If you tried to zip a file that is greater than 4 gigabytes, WinZip versions earlier than WinZip 9.0 would issue the following message:
The file is too big to be stored in a Zip file and will be skipped.
These versions also limited the number of files and folders to 65,535. This number limit and the size limit above are both limitations of the Zip file format.
The current release of WinZip and the WinZip Command Line Support Add-On include the Zip64 extension to the Zip file format. This was introduced in WinZip 9.0 and WinZip Command Line Support Add-On 1.1 (released in 2004).
For all practical purposes, the Zip64 extended format eliminates these size and number restrictions. Using the extended format, the member file size, Zip file size, and number of member files you can add to a Zip file are limited only by your system's resources.
With the Zip64 extensions to the Zip file format enhancement, Zip files of 18,446,744,073,709,551,615 bytes (2 to the 64th power) are possible. This is 16 exabytes, or over 16 billion gigabytes. Over 4 billion files and folders can be included in a Zip file.
In order to take full advantage of the extended format, both your Windows version and your storage location (hard drive, external drive, etc) must support such large files. Essentially, any of the operating systems on which WinZip can be installed (Windows 7, Windows Vista, Windows XP, and their server versions) support large files. Many external drives come preformatted as FAT32 for greater compatibility and would need to be converted to NTFS.
Members of the Windows 9X family of operating systems (Windows Me, Windows 98, Windows 95) are no longer supported by Microsoft or by WinZip. These operating systems use FAT or FAT32 file systems which do not have support for very large files. For a detailed description of the NTFS and FAT file systems and their size limitations, please read the Microsoft TechNet article Working with File Systems.
Note: One additional limit involves the maximum length of a fully qualified file name (path + name). The maximum length is 250 characters. This is a limit built into Windows. It is not a WinZip limit nor a limit of the Zip file format. Although there is no direct limit on the number of folder levels allowed, the character length limit prevents too many levels from being added.
If you have any questions about this information, please email Technical Support.