Difference Between ZIP and RAR


ZIP and RAR are widely used file formats for data compression. Data compression is the process of reducing the size of data. It uses an encoding scheme, which encodes the data using a less number of bits than the original data. In addition to compressing data, ZIP also supports archiving. A ZIP file could be made up of several files that are compressed or stored without compressing. RAR (Roshal Archive) is also a file format that supports file spanning in addition to data compression.

What is ZIP?

ZIP is a file format that supports data compression and archiving. Originally created in 1989 by Phil Katz, today ZIP is supported by many software including the built-in ZIP support provided by the Windows operating systems And Mac OS X (versions 10.3 and later). Typically, the file extensions “.zip” or “.ZIP” and MIME media type application/zip are used for ZIP files. ZIP can be used to archive multiple files and the compression is optional when archiving. If compression is used for an archive, then it is applied on separate files. 32-bit CRC algorithm is used in ZIP format. To increase the safety of data, ZIP includes two copies of the archive directory structure. ZIP format supports compression methods such as DEFLATE, BZIP2, LZMA (EFS), WavPack, PPMd, etc. One advantage in ZIP format is that since it does the compression of files in an archive separately, the files could be randomly accessed. In addition, the user has the option to apply different compression algorithms to different file types to obtain better compression. Password-based symmetric encryption is supported with ZIP.

What is RAR?

RAR is also a data compression and archiving format. It was developed by Eugene Roshal and uses the file extensions .rar for the data volume set and .rev for the recovery volume set. The compression algorithm used in RAR is a closed algorithm. A compression method based on Lempel-Ziv (LZSS) and prediction by partial matching (PPM) compression is used in the current RAR version (version 3). Only commercial software such as WinRAR could be used to create RAR files. Third party software such as WinZip, RarZilla, 7-Zip, IZArc, PeaZip, Zipeg, etc. could be used to read RAR files. By creating “recovery volumes” when creating RAR files, one can reconstruct missing files.

What is the difference between ZIP and RAR?

Even though both ZIP and RAR are data compression and file archiving formats, they have some differences. Compressing data using RAR will be slower than compressing the same data using ZIP. But RAR can achieve a better rate of compression than ZIP. Creating RAR files would require proprietary software such as WinRAR, but unpacking RAR files could be done using many free software. On the other hand, lot of commercial and open source tools and libraries are available for ZIP. The minimum size allowed for a ZIP file is 22 bytes, whereas the minimum size of a RAR file is 20 bytes. Maximum size of a standard ZIP file is 4 GiB (232-1) and the maximum size of a RAR file is 8 Exabytes (263-1).