Winzip 15 compression and archiving software

The most popular way to reduce the size of computer files is to compress them, a process commonly known as ‘zipping' after the most popular compression format, the .zip file.

It's useful for getting more files on a disk, sending email attachments more quickly and tidying collections of files into convenient archives. Winzip is the official Windows software for creating and working with Zip files, but similar basic functionality has been built into Windows for 10 years, and free alternatives such as 7-Zip work just as well.

Winzip offers two things Windows on its own doesn't: convenience and tighter compression. Under Windows 7 or Vista, a Winzip gadget is added to the desktop, to which you can drag and drop files to have them zipped and saved or zipped and attached to emails in one action. It's neat and handy and you get the choice to automatically resize graphics to one of several standard sizes. This is very useful when sending pictures to people with slow internet connections, though it's a shame there was no option to customise the picture size.

We compressed two picture files, totalling 48.4MB, into Winzip 15's high-compression zipx format and the standard zip format. We also used 7-Zip and the Windows 7 compression tool. The zipx high-compression format gave the smallest file (9.7MB), but only a little better than 7-Zip (10.8MB).

Both Winzip's standard zip and the Windows-created zip were 13.5MB. Winzip was fastest at creating a standard zip at 5.6 seconds, two seconds faster than Windows, and 14 seconds faster than 7-Zip.

Unfortunately, zipx files can only be read by version 12 or later of Winzip and not other programs.

Since the last version Winzip has used a ribbon interface similar to that in Microsoft Office, though this only works if you are running it on Windows 7 or Vista. The program can also encrypt files for security and can uncompress files created by other compression tools, such as those in RAR, TAR and CAB formats.

The Pro version of Winzip 15 (£17 extra) includes a backup tool and advanced photo-handing abilities. The basic one is not very expensive, but given that Windows and the free 7-zip do a good-enough job it's hard to recommend.