BZIP2 (.bz2)

MIME type: application/x-bzip2.
BZIP2 compression method and file format.
General-purpose lossless compression method.
Occasionally used for archiving data on Unix systems and for exchanging files on the internet.
Binary format.
Compresses data using a combination of the Burrows-Wheeler transform and Huffman entropy coding.
Stores a single file.
Typically used in combination with TAR.
Developed and maintained by Julian Seward.
Introduced in 1996, released as version 1.0 in 2000.

Import and ExportImport and Export

  • Import["file.ext.bz2"] uncompresses and imports a BZIP2 compressed archive.
  • Export["file.ext.bz2", expr] exports any expression expr to a BZIP2 compressed file whose format is implied by the file name extension .ext.
  • Import["file.bz2"] uncompresses file.bz2 and imports file, automatically inferring the format from the file contents.
  • Import["file.bz2", "format"] uncompresses a BZIP2 file and imports it as .
  • Since Mathematica can automatically recognize all common file compression and archive formats, it is never necessary to specify as a format in the second argument of Import.
  • Import["file.ext.bz2", elem] imports the specified element from file.
  • Import["file.ext.bz2", {elem, suba, subb, ...}] imports a subelement.
  • Import["file.ext.bz2", {{elem1, elem2, ...}}] imports multiple elements.
  • The import format can be explicitly specified with Import["file.bz2", {"format", elems1, elems2, ...}].
  • Export["file.ext.bz2", expr, elem] creates a BZIP2 compressed .ext file by treating expr as specifying element elem.
  • Export["file.ext.bz2", {expr1, expr2, ...}, {{elem1, elem2, ...}}] treats each as specifying the corresponding .
  • Export["file.ext.bz2", expr, opt1->val1, ...] exports expr with the specified option elements taken to have the specified values.
  • The export format and BZIP2 compression method can be explicitly specified with Export["file", exprs, {"BZIP2", "format", elems}].
  • See the reference pages for full general information on Import and Export.
  • ImportString and ExportString can handle BZIP2 compressed data.


  • The BZIP2 format itself does not support Import or Export elements.
  • Import elements of the BZIP2-compressed file:
  • "Elements" elements and options available in this file
    "Rules"full rules for each element and option
    "Options"rules for options, properties, and settings
  • Import["file.ext.bz2", "Elements"] returns the names of elements available in , effectively unpacking the compressed archive before importing the enclosed file.

ExamplesExamplesopen allclose all

Basic Examples (2)Basic Examples (2)

Export a string to a BZIP2-compressed text file:

Click for copyable input

Convert the previous output back to a Mathematica string:

Click for copyable input

Export graphics to a BZIP2-compressed PNG file:

Click for copyable input

This gives the available Import elements of the PNG file:

Click for copyable input

When importing any element from a BZIP2 file, Mathematica automatically uncompresses it:

Click for copyable input
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