List of file extensions

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This is a list of common file extensions. Keep in mind that extensions are arbitrary and, whenever there's any doubt, the file command will generally provide a more accurate indicator of file contents than the extension.


  • .1, etc. - man pages generally fall into numerical categories (though there are others) and have a suffix indicating the section. Logrotate also names old log file with an extra numerical extension.


  • .asm - assembly language source code
  • .au - Sun audio file


  • .blend - Blender 3D scene
  • .bmp - Bitmap image format
  • .bz2 - a file processed with bzip2 compression (see .tar)


  • .c - C source code
  • .class - Java class, compiled bytecode
  • .conf - configuration file
  • .cfg - configuration file
  • .cpp - C++ source code
  • .cc - C++ source code (not as common as *.cpp)
  • .css - CSS, Cascading StyleSheet
  • .csv - a plain text file containing comma separated values


  • .db - Berkeley DB
  • .deb - Debian package
  • .desktop - Desktop entry, standard link/shortcut/launcher format
  • .diff - patch/difference file generated by diff
  • .dtd - DTD, Document Type Definition for XML data




  • .gif - image file which uses the patented LZW compression algorithm
  • .gz - a file processed with gzip compression (see .tar)


  • .h - header file
  • .html/*.htm - HTML



  • .jar - Java Archive zip compressed file containing Java classes/sources
  • .java - Java source file


  • .kwd - KDEs native format for their Kword word processor
  • .ksp - KDEs native format for their Kspread spreadsheet application
  • .kss - KDEs screensaver format


  • .log - logging data from some application, usually in plain text format


  • .m3u - playlist file, originates from WinAmp
  • .m4a - compressed MPEG-4 audio file without DRM
  • .m4p - compressed MPEG-4 audio file with DRM
  • .md5 - file containing an md5sum for a single file. IE: foobar.iso.md5 contains the md5sum for foobar.iso
  • .md5sums - file containing a list of MD5 checksums, generated and used by md5sum
  • .mo - Compiled message catalog, generated and used by GNU gettext
  • .mpg or .mpeg - compressed video file
  • .mp3 - compressed MP3 audio file



  • .patch - patch file, generated by diff, to be used with patch
  • .pdf - PDF, Adobe Portable Document file.
  • .php - PHP source file
  • .phps - PHP source file in which the source is intended to be displayed rather than executed
  • .phtml - PHP source file (uncommon)
  • .pl - Perl source code
  • .pls - a playlist file (file of filenames or URLs)
  • .png - PNG image file
  • .pov - source code for the povray ray tracer
  • .properties - value containing configuration values, used by Java applications
  • .ps - postscript file. Like pdf, but without form functionality.
  • .py - python script
  • .pyo - python optimized bytecode
  • .pyc - python compiled bytecode


  • rc - not really an extension, but often found at the end of 'run control' (or 'resource configuration') files such as 'bashrc'.
  • .rdf - "Resource Description Framework" file, XML based format
  • .rpm - originally a Red Hat package (the RedHat Package Manager) but now many distros are rpm based.
  • .rtf - rich text format. A Lowest common denominator format for exchanging documents between different word processors


  • .s or .S - assembly language source code
  • .sh - shell script (as with nearly all extensions, this is optional)
  • .so - Shared object/library file


  • .tar - a file archived with tar (the tape archiver) - often also compressed with gzip, bzip2, etc., in which case it will have a double extension of 'tar.gz', '.tar.bz2', etc.
  • .tgz - possibly a .tar.gz file with the shorter extension but more likely these days to be a Slackware package like a .deb or .rpm
  • .tga - Targa image file
  • .ttf - TTF (True Type) font
  • .txt - plain text file.


  • .wav - uncompressed audio format


  • .xbel - XML based bookmarks file
  • .xsd - XML Schema
  • .xml - XML file
  • .xsl - XSL stylesheet
  • .xpm - X pixmap


  • .Z - rarely seen anymore, a compressed file, often tarred as .tar.Z
  • .zip - Compressed Archive. More common on Windows, but can be read/written on UNIX using zip and unzip commands