Compression Algorithm Comparison
These charts compare how well multiple compression ratios compress and how quickly they do it. At the end, the winners of the test are announced. For this test, images, text, and binary were all compressed. The algorithms tested were: 7-zip, Bzip2, gzip, Deflate, Deflate64, SIT, SITX, and RAR.
Speeds:
In these charts, the smaller the bar is, the faster the algorithm is. Gzip is the fastest at both compression and decompression.
Compression Ratios:
For these charts, the larger the bar is, the smaller the file is. 7-zip creates the smallest files with the StuffItX algorithms trailing slightly. Bzip2 and gzip also have very good compression.
This chart displays the overall speed of each algorithm. The smaller the strip, the faster the algorithm compresses/decompresses. The left side is the compression and the right side is the decompression. As you can see, 7-zip has a very large compression time, but it's decompression time is very good. The StuffIt algorithms generally have a similar compression and decompression rates. Also, gzip is the fastest at both compression and decompression.
This is an overall comparison of the compression. The greater the area of the strip, the smaller the file. As you can see, 7-zip makes the smallest file, and the gzip algorithm is almost as good as the StuffItX algorithms.
This is simply a chart with a general interpretation of the results.
Summary:
When you have no worries about speed, 7-zip is generally the best format to use. It compresses better than any other algorithm. However, it is very slow at compression. It should mostly be used for archiving files or sending files over very slow connections. The StuffItX algorithms provide very high compression ratios for a high speed compression rate, however they have the slowest decompression rate, and so they are not great for the recipient. Also, although StuffItX can be decompressed using a free program, the compressor is not free, and there is no decompresser for Linux. Generally StuffIt and StuffItX are used on Macintosh. Deflate and Deflate64 are fairly fast and compress decently, however they have the advantage of being very widespread. Most of the time a .zip file will either be Deflate or Deflate64, although DCL Implode (very uncommon) and Bzip2 are also used. Bzip2 is a fairly new compression algorithm, but it has a fairly good compression ratio. Gzip wins the speed contest and yet has a very good compression ratio. RAR performs fairly well overall, however it does not perform as well as Deflate in both speed and compression ratio, and since it is also not as widespread, it may not be as good a choice.
Winners:
The two winners are 7-zip and gzip, each for its own reason. 7-zip offers the absolute best compression ratio while still offering good decompression speeds. However, for day to day use, stick with gzip. With its lightning fast speeds and compression ratios that fall only a tad short of Bzip2 and StuffItX, it is the over-all winner. Originally there were to be three winners. A speed winner, a compression ratio winner, and an overall winner. However, gzip wins both the speed and the overall. gzip is also very popular for open source projects.
7-zip is created by the 7-zip project and is open source. Bzip2 is another open source compression algorithm available here. Tarball is not a compression format, but information about them can be found here. Gzip is unpatented and open source and is available at gzip.org. Deflate, also open source, can be found here. Delate64 is a registered trademark of PKWARE, the inventors of the .zip file. For more information visit their site here. StuffIt is a registered trademark of Aladdin Systems. More information can be found here. RAR is available here.
Note about StuffItX: In this test there were two different StuffItX algorithms. The first is on the setting to choose how to compress based on the file (Method 5 in StuffIt). The second is the best speed/size trade-off. (Method 3 in StuffIt).