Computer Tips From A Computer Guy

7-Zip VS WinZip V.12 - Best compression method

Posted: 18 Mar 2009 03:34 AM PDT

A few nights ago, I have blogged about 7-Zip VS WinZip VS WinRar. It was a controversial test because as one reader commented, I did not use the other compression algorithms available in WinZip. Upon realizing that, I did another test to satisfy this burning question: Could the best and latest compression method of WinZip beat 7-Zip?

To make sure I use the best compression algorithm, I have enabled it during WinZip's installation:

For the test I have my 32 document files totaling about 54.1 MB:

Those 32 files are Windows Live Writer files. In my opinion, this file type ideally suits this test since it is a format that contains images and text files inside it (just like how doc formats work). First I used 7-Zip to get a benchmark result. The output was a 7z file with a size of 25.1 MB:

Then I used WinZip V.12's best compression algorithm to generate a zip file. The result is 25.2 MB:

I made sure I used the optimized algorithm by checking the options:

Clearly, 7-Zip still beat WinZip's latest algorithm but only for a few bytes.

If we subtract the exact difference of those two results there is a difference of 111,575 bytes or about 0.2% with respect to the original unzipped file:

Tool	Output in Bytes
WinZip	26,444,067
7-Zip	26,332,492
Delta	111,575

0.2% difference is not much of a difference but in terms of who's better at document formats, I think it is safe to assume that 7-Zip could still beat WinZip although the margin would be slim and negligible to most casual users.

Now since WinZip is advertizing V.12's new JPEG compression technology, I pitted it again against 7-Zip:

The files I zipped are 71 JPEG files with 81MB in total size. We already know that 7-Zip is not good at JPEGs so I did not expect it to gain on this test. On the other hand , I was really impressed with WinZip's 20% margin! This is a great improvement for the whole zipping industry since now we can debunk the idea that JPEGs are not worth zipping.

Do you know of other tools that could beat WinZip's JPEG compression algorithm? Post them on the comments section and I will give them all a try.