Instead of wasting server resources and bandwidth you can get the browser client to do it for you and JSZip helps to create .Zip files with Javascript.

The biggest issue with JSZip is that the filenames are very awkward, Firefox generates filenames such as a5sZQRsx.zip.part, and Safari isn’t much better with just Unknown.

Sadly there is no pure Javascript solution to this. However Downloadify can be used to download files to a user’s computer with a filename that you can choose.