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In my application I need do compress of logs that are text files.

Seems that bzip2 and gzip have the same compression ratio.

Is that correct?

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migrated from Dec 1 '11 at 12:49

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xz (from xz-tools or 7z from p7zip, it is very like lzma) is the best. bzip2 is better than gzip. – osgx Dec 1 '11 at 12:36
up vote 3 down vote accepted

Normally, bz2 has a better compression ratio, combined with better recoverability features.

OTOH, gz is faster.

xz is said to be even better than bz2, but I don't know the timing behaviour.

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xz is slower than bzip2. – osgx Dec 1 '11 at 14:46

Maybe you could have a look to those benchmarks, especially the part testing the log files compression.

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Last update of is June-2011 (answer updated in Oct-2015)
Therefore this website does not mention
the current champion text compressor worldwide:



Byron Knoll is actively developping cmix as libre software (GPL) since 2013 based on the book Data Compression Explained by Matt Mahoney. Matt Mahoney also maintains some of the above benchmarks and proposes ZPAQ (WP), a command line incremental archiver.

If you prefer a more standard tool (requiring less RAM) I recommend:


lrzip is an evolution of rzip by Con Kolivas.
lrzip stands for two names: Long Range ZIP and Lzma RZIP.
lrzip is often better than xz (another popular compression tool).
Alexander Riccio also recommends lrzip.

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bz2 has tighter compression, the algorithm has more options to look for redundancy to compress away.

gzip is in much more tools, and is more cross platform. More Windows tools can deal with .gz files. It's part of http, so even web browsers can understand it.

On linux, there are tools that let you work on compressed files directly. zgrep and bzgrep can search in compressed files.

If just on Linux, I'd use bzip2, for the slightly better compression ratios.

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xz compresses much better than bz2, but takes more time. So, if maximum compression is your goal and space on your hard drive is at a premium (which is my case with one drive at 98% full - while I reorganize my file systems), and you can fire off a script to do the work - take a break and come back in 5 minutes.

unxz is very fast to uncompress in my experience - which is a good thing for me on a daily basis.

bz2 is faster to compress than xz, but does not appear to achieve the compression results of xz.

The only way to make these assessments is to run benchmarks against a mix of common files you normally would compress/decompress, and vary the parameters to see which comes out on top.

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i have made a benchmark to test to compress the following:
204MB folder (with 1,600 html files)

7zip =>     2.38 MB
winrar =>   49.5 MB
zip =>      50.8 MB
gzip =>     51.9 MB

so the 7zip is the best among them you can get it from here

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