ZIP vs RAR

ZIP and RAR are two popular file formats in the Windows world. They have similarities, since both of them provide lossless file compression. But they have some fairly significant technical and philosophical differences too. Here’s a look at ZIP vs RAR and why the two file formats have coexisted side by side for decades.

Philosophical differences between ZIP and RAR

ZIP vs RAR
ZIP vs RAR didn’t launch another compression war the way ZIP vs ARC did. The two file formats have coexisted for more than a quarter century.

The major differences between ZIP and RAR is that ZIP is an open standard, while RAR is proprietary. Phil Katz patented his file format, but he permitted others to use the standard. This sped adoption for the ZIP file format, because people could create versions of ZIP for computer platforms Katz wasn’t interested in supporting. Zip tried to be open and better than its incumbent.

Eugene Roshal, the creator of RAR, took a different approach. RAR is a closed standard. Third parties can write RAR decompressors, but they can’t write a utility to create RAR files. Roshal bet that he could carve out a niche for himself by creating a slightly better file format and keeping it less open than Katz had, to keep someone else from usurping the format the way Nico Mak usurped ZIP from Phil Katz.

Zip vs RAR: Free software vs proprietary

On one hand, keeping the file format closed probably limited RAR’s adoption. On the other hand, WinRAR has remained a viable product for more than a quarter century. While Phil Katz died a broken man, Eugene and Alexander Roshal have at least been able to make a living off Eugene Roshal’s invention. Eugene Roshal is the developer while his older brother Alexander Roshal handles the legal matters.

The free, open model certain spurs adoption. The Roshals tried a proprietary model, betting that they could survive, even if it meant being a niche product. It seems they were right. If Phil Katz was the IBM of compression, Nico Mak was the Compaq, and Eugene Roshal is the Apple.

Advantages of ZIP

ZIP’s ubiquity has some advantages. There are dozens of programs that can create and extract ZIP archives. Some are easier to use than others. Some are faster than others. Still others create slightly smaller files. And Zip existed on almost every operating system imaginable. I had an unzip utility for CP/M that I used in the early 90s. I used Info-Zip on my Amiga, and discovered, to my surprise, that if I used its maximum compression option, it created slightly smaller files than PKZIP on MS-DOS with its maximum compression option. The files remained compatible. This showed the upside of competition.

While 8-bit systems generally weren’t powerful enough to create Zip files, at least I could extract them. And I could create Zip files on any 16-bit or 32-bit operating system that had a command line. The Info-Zip project provided versions for Amiga, Linux, OS/2, DEC VMS, DOS and Win32, and others I’m forgetting about.

In the mid 90s when my friends started sending me RAR files, it annoyed me. I had to install yet another unfamiliar program to create and extract them, and I found early versions of WinRAR clumsy. Extracting them has gotten better over the years, but on any given platform, there’s generally one piece of software that can create them.

Advantages of RAR

ZIP compresses files by about 62 percent, on average. RAR is slightly more efficient, generally compressing the same files by about 64 percent.
I never joined the RAR fan club, but RAR does have some advantages over Zip. First, it creates smaller files in most cases. Sometimes the difference is slight but sometimes it’s significant. It just depends on the type of data. On average, I’ve found RAR creates files about two percent smaller than Zip when they’re both using their maximum compression settings.

But the bigger advantage is its ability to split files. Most Zip utilities can’t split a large file into several parts. RAR can. I used to think only software pirates needed this feature, to divide enormous files into smaller parts that are easier to download. And indeed, that is a popular use case for RAR.

But in my current line of work, I have to use this feature from time to time. It isn’t a feature I need often, but when I need it, I need it badly. In business, sometimes Zip vs RAR is important.

Here’s my use case. Sometimes I have to send a file to a vendor for troubleshooting, usually a log file or a PCAP file. Their ticketing system always has a file limit. The file limits are pretty generous, usually around 100 megs. Usually the files I have to send them are really repetitive, so they compress well. But once or twice a year, I end up with an enormous file that won’t compress to any less than 101 megs, no matter what I do. With RAR, I can create a multi-part archive that splits the file into pieces no larger than 100 megs and get the file to the vendor.

I imagine this use case is what keeps the Roshal brothers in business. When you need to send large files back and forth, the $29 registration fee is a bargain.

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