How to determine compression method of a ZIP/RAR file

algorithm compression zip rar
Intenex picture Intenex · Aug 1, 2011 · Viewed 27.8k times · Source

I have a few zip and rar files that I'm working with, and I'm trying to analyze the properties of how each file was compressed (compression level, compression algorithm (e.g. deflate, LZMA, BZip2), dictionary size, word size, etc.), and I haven't figured out a way to do this yet.

Is there any way to analyze the files to determine these properties, with software or otherwise?

Cheers and thanks!

Answer

atatko picture atatko · Jul 2, 2012

This is a fairly old question, but I wanted to throw in my two cents anyway since some of the methods above weren't as easy for me to use.

You can also determine this with 7-Zip. After opening the archive there is a column for method of compression:

7zip properties

Related questions

An efficient compression algorithm for short text strings

I'm searching for an algorithm to compress small text strings: 50-1000 bytes (i.e. URLs). Which algorithm works best for this?

Read More
How does one make a Zip bomb?

This question about zip bombs naturally led me to the Wikipedia page on the topic. The article mentions an example of a 45.1 kb zip file that decompresses to 1.3 exabytes. What are the principles/techniques that would be used to create …

Read More
Data Compression Algorithms

I was wondering if anyone has a list of data compression algorithms. I know basically nothing about data compression and I was hoping to learn more about different algorithms and see which ones are the newest and have yet to …

Read More