What is the difference between “legacy” and “best method” compression?

WinZip^® E-Mail Companion allows you to choose between two different compression methods when it creates Zip files. The Legacy method creates Zip files with the most compatibility with other Zip utilities, but may not provide the best compression to create the smallest Zip files possible. The Best method will provide better compression and create smaller Zip files but these files may not be compatible with some Zip utilities.

Legacy (Zip 2.0)

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. 'Legacy (Zip 2.0)' is your best choice when your mail recipient's Zip utility is unknown, or known to use older technology. WinZip E-Mail Companion actually uses the highest compression setting for the deflate method or ‘maximum deflate’. This way you get the smallest Zip files possible with this method.

Best method

The Best method option allows 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 WinZip 11 or another Zip file utility that is compatible with all of WinZip’s advanced compression methods.