WinZip® and WinZip E-Mail Companion allow you to choose between two different compression methods when creating Zip files (.zip or .zipx)*. The Legacy method creates Zip files with the most compatibility with other Zip file utilities, but may not provide the best compression to create the smallest Zip files possible. The Best method option will provide better compression and create smaller Zip files but these files may not be compatible with some Zip utilities.
.Zip Legacy compression (maximum compatibility)
The Legacy (Zip 2.0) compression option uses a traditional data compression algorithm, known as deflate, that is supported by all versions of WinZip and virtually all other Zip file utilities. The deflate method is generally considered to be a good all-purpose compression algorithm for most types of files. .Zip: Legacy compression is your best choice when your mail recipient's Zip utility is unknown, or known to use older technology. WinZip and WinZip E-Mail Companion actually use the highest available compression setting for the deflate method or maximum deflate. This way you get the smallest, highly compatible Zip files possible.
.Zipx Best method (smallest size)
The Best method option allows WinZip and WinZip E-Mail Companion to choose the best compression method for each file, based on the file type. You may want to choose this option if compressed file size is a primary concern. Be sure that the recipients of your e-mail are using the latest version of WinZip, or another Zip file utility that is compatible with all of WinZip's advanced compression methods.
*Note: WinZip E-Mail Companion was released before the implementation of the .zipx file extension. When using Best method in the WinZip E-Mail Companion, Zip files will have the .zip extension and will not use all of the possible compression methods available in the latest version of WinZip.
