What Is a File Extension?

Posted by admin at September 9, 2021

A file extension, sometimes called a file suffix or a filename extension, is the character or group of characters after the period that makes up an entire file name.

A filename extension, file extension or file type is an identifier specified as a suffix to the name of a computer file. The extension indicates a characteristic of the file contents or its intended use. A filename extension is typically delimited from the filename with a full stop, but in some systems it is separated with spaces. Wikipedia

Audio file formats by file extensions

There are several audio file formats, standards, and file extensions used today. Below is a list of the most common audio file extensions.

.aif – AIF audio file

.cda – CD audio track file

.mid or .midi – MIDI audio file.

.mp3 – MP3 audio file

.mpa – MPEG-2 audio file

.ogg – Ogg Vorbis audio file

.wav – WAV file

.wma – WMA audio file

.wpl – Windows Media Player playlist

Compressed file extensions

compressed files

Most computer users are familiar with the .zip compressed files, but there are other types of compressed files. Below is a list of the most common compressed file extensions.

.7z – 7-Zip compressed file

.arj – ARJ compressed file

.deb – Debian software package file

.pkg – Package file

.rar – RAR file

.rpm – Red Hat Package Manager

.tar.gz – Tarball compressed file

.z – Z compressed file

.zip – Zip compressed file

Disc and media file extensions

When making an image of a disc or other media, all of the contained files are saved to an image file. Below are the most common disc image file extensions.

.bin – Binary disc image

.dmg – macOS X disk image

.iso – ISO disc image

.toast – Toast disc image

.vcd – Virtual CD

Data and database file extensions

A data file could be any file, but for this list, we’ve listed the most common data files that relate to data used for a database, errors, information, importing, and exporting.

.csv – Comma separated value file

.dat – Data file

.db or .dbf – Database file

.log – Log file

.mdb – Microsoft Access database file

.sav – Save file (e.g., game save file)

.sql – SQL database file

.tar – Linux / Unix tarball file archive

.xml – XML file

E-mail file extensions


Below is a list of the most common file extensions for e-mail and related files.

.email – Outlook Express e-mail message file.

.eml – E-mail message file from multiple e-mail clients, including Gmail.

.emlx – Apple Mail e-mail file.

.msg – Microsoft Outlook e-mail message file.

.oft – Microsoft Outlook e-mail template file.

.ost – Microsoft Outlook offline e-mail storage file.

.pst – Microsoft Outlook e-mail storage file.

.vcf – E-mail contact file.

Executable file extensions

java archive

The most common executable file are files ending with the .exe file extension. However, other files can also be run by themselves or with the aid of an interpreter.

.apk – Android package file

.bat – Batch file

.bin – Binary file

.cgi or .pl – Perl script file

.com – MS-DOS command file

.exe – Executable file

.gadget – Windows gadget

.jar – Java Archive file

.msi – Windows installer package

.py – Python file

.wsf – Windows Script File

Font file extensions

Below are the most common file extensions used with fonts.

.fnt – Windows font file

.fon – Generic font file

.otf – Open type font file

.ttf – TrueType font file

Image file formats by file extension

JPEG example

There are many different image types and image file extensions that can be used when creating and saving images on the computer. Below is a list of the most common image file extensions.

.ai – Adobe Illustrator file

.bmp – Bitmap image

.gif – GIF image

.ico – Icon file

.jpeg or .jpg – JPEG image

.png – PNG image

.ps – PostScript file

.psd – PSD image

.svg – Scalable Vector Graphics file

.tif or .tiff – TIFF image

Internet-related file extensions

The Internet is the most used resource on the computer and because web servers supply the files, there are many different file extensions utilized. Below are a list of the most common file extensions on the web.


Image file extensions, video file extensions, and other extensions listed on this page could also be included with these file extensions mentioned below.

.asp and .aspx – Active Server Page file

.cer – Internet security certificate

.cfm – ColdFusion Markup file

.cgi or .pl – Perl script file

.css – Cascading Style Sheet file

.htm and .html – HTML file

.js – JavaScript file

.jsp – Java Server Page file

.part – Partially downloaded file

.php – PHP file

.py – Python file

.rss – RSS file

.xhtml – XHTML file

Presentation file formats by file extension

Today, there are a few programs that can create a presentation. Below is a list of the most common file extensions associated with presentation programs.

.key – Keynote presentation

.odp – OpenOffice Impress presentation file

.pps – PowerPoint slide show

.ppt – PowerPoint presentation

.pptx – PowerPoint Open XML presentation

Programming files by file extensions

Many file extensions are used for programs before they are compiled or used as scripts. Below is a list of the most common file extensions associated with programming.


Many of the Internet-related file extensions could also be included with these file extensions mentioned below.

.c – C and C++ source code file

.cgi and .pl – Perl script file.

.class – Java class file

.cpp – C++ source code file

.cs – Visual C# source code file

.h – C, C++, and Objective-C header file

.java – Java Source code file

.php – PHP script file.

.py – Python script file.

.sh – Bash shell script

.swift – Swift source code file

.vb – Visual Basic file


There are hundreds of programming languages and the above list is only a small fraction of the most common file extentions.

Spreadsheet file formats by file extension

Below are the most common file extensions used to save spreadsheet files to a computer.

.ods – OpenOffice Calc spreadsheet file

.xls – Microsoft Excel file

.xlsm – Microsoft Excel file with macros

.xlsx – Microsoft Excel Open XML spreadsheet file

System related file formats and file extensions


Like all other programs, your operating system uses files and has file extensions that are more common than others. Below is a list of the most common file extensions used on operating systems.


The executable file extensions and all other files could also be included in this list.

.bak – Backup file

.cab – Windows Cabinet file

.cfg – Configuration file

.cpl – Windows Control panel file

.cur – Windows cursor file

.dll – DLL file

.dmp – Dump file

.drv – Device driver file

.icns – macOS X icon resource file

.ico – Icon file

.ini – Initialization file

.lnk – Windows shortcut file

.msi – Windows installer package

.sys – Windows system file

.tmp – Temporary file

Video file formats by file extension


Today, several file types are associated with video files to add different types of compression, compatibility, and DRM to video files. Below is a list of the most commonly found video file extensions.

.3g2 – 3GPP2 multimedia file

.3gp – 3GPP multimedia file

.avi – AVI file

.flv – Adobe Flash file

.h264 – H.264 video file

.m4v – Apple MP4 video file

.mkv – Matroska Multimedia Container

.mov – Apple QuickTime movie file

.mp4 – MPEG4 video file

.mpg or .mpeg – MPEG video file

.rm – RealMedia file

.swf – Shockwave flash file

.vob – DVD Video Object

.wmv – Windows Media Video file

Word processor and text file formats by file extension

Creating text files and using a word processor is one of the most common tasks on a computer. Below is the most common file extensions used with text files and documents.

.doc and .docx – Microsoft Word file

.odt – OpenOffice Writer document file

.pdf – PDF file

.rtf – Rich Text Format

.tex – A LaTeX document file

.txt – Plain text file

.wpd – WordPerfect document


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