Free conversion of a .rar file?

[Aaralli]

I encounter a lot of .rar files, and my free trial of WinZip has expired. What is a reliable, free way to convert .rar files into something my computer can use?

[PlayStation 2]

...7-Zip? I'm assuming you're converting the .rar files into .zip, anyways.

[Skiiwee29]

7zip all day

[Aaralli]

Just now, Skiiwee29 said:

7zip all day

 

1 minute ago, Dan Castellaneta said:

...7-Zip? I'm assuming you're converting the .rar files into .zip, anyways.

Thanks! I don't really know anything about software like this and what I should and shouldn't use, so glad I have you lovely humans for this.

[Votivee]

7-zip is actually faster than winrar/winzip

[Dat Guy]

Buy WinRAR. I did.

 

4 hours ago, Votivee said:

7-zip is actually faster than winrar/winzip

Unless you want to have a good compression, which is where WinRAR easily outperforms 7-zip, according to the diagram. WinZip is not a part of it though. Please show your numbers.

 

edit:

Also, UnRAR is available free of charge. You can use any other archiving application afterwards.

[mariushm]

@Dat Guy You're incorrect.

 

7zip outperforms WinRAR at everything, if you know what you're doing.

If you're using the defaults  (ex fast, best compression), then WinRAR may get you better compression out of the box, but 7zip gives you a lot of flexibility and you're not as restricted.

 

For example:

* IF you want backwards compatibility with people that use older WinRAR on unRAR programs, RAR 4 format is limited to a 4 MB dictionary. IF you go with RAR5, the dictionary size can increase to 1 GB.  In contrast, 7zip will let you use even 1.5 GB dictionary size and its supported regardless of version you have.

* WinRAR is limited to maximum 32 threads, not sure about 7zip but I think it can do more. If you get a 32+ core processors like the current Threadripper/Epyc, you won't use them to the max with WinRAR, unless you run multiple instances at same time.

* WinRAR will auto pick the number of threads to compress, while 7zip allows you to use only 1 thread if you want absolutely bestest compression possible (more threads results in slightly lower compression ratio).. I think you can select thread count from command line but who does that

* WinRAR 5 is basically some variant of LZMA or LZMA2 algorithm if I remember correctly, which is the default of 7zip since it was launched 

* WinRAR has the single algorithm for version 5, while 7zip allows you to use algorithms like BZip2 or PPMd if you plan to archive mostly TEXT documents (these algorithms work best with text, LZMA and LZMA2 work best with everything)

 

As a proof of what i mean, I downloaded Google Chrome source code from here: https://github.com/chromium/chromium

Select download as zip, you'll get a 1.2 GB zip which unpacks in 2666 MB.

It's a good mix of files to test a compressor, it has source code, binary files (DLLs), images, archives (jar files) etc etc ... 317,614 Files, 25,096 Folders

 

892,095,469 : rar v4.0, best compression, solid, 4 MB dictionary (best possible, RAR4 compatibility)

842,239,932 : 7zip, LZMA2, 32 MB (weaker than LZMA, but multi-threaded)

820,339,662 : rar v5.0, best compression, solid, 32 MB dictionary (default RAR5 best + solid)

820,076,129 : 7zip, LZMA, 32 MB

815,697,362 : rar v5.0, 256 MB dictionary + solid

812,442,663 : 7zip, LZMA2, 256 MB dictionary

 

I didn't test with more than 256 MB dictionary because this laptop only has 8 GB of memory (512MB dict + 4 threads requires 12GB of ram to compress) and because usually the effectiveness of a dictionary starts to decrease at around 1/8th of the total file size.

 

So as you can see 7zip can achieve better compression than WinRAR in some modes and is more compatible with everything.

 

 

[Dat Guy]

5 minutes ago, mariushm said:

7zip can achieve better compression than WinRAR in some modes and is more compatible with everything.

(Highlighted words for other people to be less impressed by largely irrelevant numbers.)

Note that PAQ is probably the algorithm with the highest compression ration in 2019. Can I create PAQ archives in 7-zip? No? Next! - Neither can I in WinRAR, by the way. You might see my point though.

 

Regarding compatibility: The format we're talking about here are RAR files. How exactly does 7-zip excel in RAR archiving? (I won't even start with the fact that WinRAR can extract 7z files as well...)

[mariushm]

9 minutes ago, Dat Guy said:

Regarding compatibility: The format we're talking about here are RAR files. How exactly does 7-zip excel in RAR archiving? (I won't even start with the fact that WinRAR can extract 7z files as well...)

No, the original question was :

 

Quote

What is a reliable, free way to convert .rar files into something my computer can use?

and 7-zip is a perfectly good solution for his needs: 100% free, no nagging, open source, available for multiple platforms (windows, linux, mac etc)

 

[Dat Guy]

So is UnRAR which does not even limit the list of target formats.

[mariushm]

UnRAR only extracts. What formats would it limit?  It only knows RAR v4.0 and RAR v5.0

 

7-zip can unpack 7-zip, RAR (using unRAR library because rar is proprietary), bz2, tar.gz, xz, it can even open ISO files so you don't have to mount a CD/DVD image.

 

... and yes, I'm familiar with the PAQ family of compressors, and with WinRK and other compressors.

Point is when it comes to balancing compression speed with compressed size and options to achieve this 7-zip is simply more versatile as I explained.

 

 

 

[Dat Guy]

1 minute ago, mariushm said:

UnRAR only extracts.

Which was exactly what was asked. It extracts into a format which the computer can understand. Everything else... well, it depends on the target operating system. Chances are that the installation of any other software is not required at all. Even Windows can zip now.

[Kilrah]

3 hours ago, Dat Guy said:

Unless you want to have a good compression, which is where WinRAR easily outperforms 7-zip, according to the diagram.

Diagram precisely shows the opposite.