What are BZ2 files, what is BZip2 compression algorithm

BZ2 extension

BZ2 extension designates a pure data compression format not providing file archival feature, its BZip2 compression algorithm is based on Burrows–Wheeler transform.

Compressed files are usually identified by .bz2 extension, and can contain a single input file.

TBZ / TAR.BZ file extension
Due this by-design limitation, on Unix/Linux systems BZip2 compression (as well as Gzip, XZ,...) is usually cascaded to TAR archive creation -  multiple files data and metadata (file attributes, date/time etc) are consolidated into a single uncompressed .tar container - producing TBZ2 file, which can be identified with TBZ, TB2, or TAR.BZ2 extension.

PeaZip features creation and extraction of BZ2 files, can read (open, test and extract) and write (compress to) BZ2 file type. Also, PeaZip can be set to use BZip2 compression as alternative algorithm for ZIP and 7Z formats, in Advanced options tab.

BZ2 file format specs

Compression speed is somewhat slower than in zip format and gzip format, which employs classic Deflate algorithm (even if correctly implemented Bzip2 algorithm can be easily made parallel, and benefit of recent multi-core CPU), but faster than more powerful compression schemes as in RAR format, 7Z format, and new ZIPX format (which can optionally use BZip2 algorithm as compressor).
Compression ratio, also, is usually intermediate between older Deflate-based ZIP/GZ files and modern RAR, 7Z, ZIPX formats.Use of BZ2 and related file types

Read more about .bz2 file type on BZip official domain, and Burrows–Wheeler transform entry on Wikipedia.

Synopsis: What is BZ2 file format extension. Bzip2 compression algorithm. What are .BZ2 compressed file type features and specifications. TAR.BZ2 and TBZ archive formats.

Topics: BZ2 file extension specs

PeaZip > FAQ > What is BZ2 extension (BZip2 compressed file format)