1. Audio
- .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.
2. Compressed
- .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.
3. Disc and media
- .bin – Binary disc image.
- .dmg – macOS X disk image.
- .iso – ISO disc image.
- .toast – Toast disc image.
- .vcd – Virtual CD.
4. Data and database
- .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.
5. E-mail
- .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.
6. Executable
- .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.
7. Font
- .fnt – Windows font file.
- .fon – Generic font file.
- .otf – Open type font file.
- .ttf – TrueType font file.
8. Image
- .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.
9. Internet
- .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.
10. Presentation
- .key – Keynote presentation.
- .odp – OpenOffice Impress presentation file.
- .pps – PowerPoint slide show.
- .ppt – PowerPoint presentation.
- .pptx – PowerPoint Open XML presentation.
11. Programming
- .c – C and C++ source code 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.
- .pl – Perl script file.
- .sh – Bash shell script.
- .swift – Swift source code file.
- .vb – Visual Basic file.
12. Spreadsheet
- .ods – OpenOffice Calc spreadsheet file
- .xls – Microsoft Excel file
- .xlsm – Microsoft Excel file with macros
- .xlsx – Microsoft Excel Open XML spreadsheet file
13. System
- .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
14. Video
- .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
15. Word processor
- .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