File Types
This page houses a computer file extension library with a brief explanation. A file extension is simply the last characters after the stop (period) in the name of a file. Files with a shared common name extension (.doc, .html and so on) are of the same type.
Extension |
Type |
File (Suffix) Characteristics |
|---|---|---|
| .aam | media file | Macromedia (Now Adobe) Shockwave. |
| .arc | archive file (obsolete) |
Open with PKZip or WinZip. |
| .asp | web page | Active server page – used to code web pages that connect to databases. |
| .au | audio | Sound file – open with player – used on older web pages. |
| .avi | video clip | Audio/Video Interleaved – movie clip – open with mplayer, or IE – see also .vlc |
| .bak | backup file | Used by many applications – often created automatically. |
| .bat | application | DOS batch file – run by double-clicking in early Windows – edit with Notepad. |
| .bmp | graphic file | Microsoft bitmap – open in MS Paint or graphics program. |
| .cab | archive | Microsoft installation achive (cabinet file) – similar to .zip archive. |
| .cfg | – | Configuration file. |
| .cgi | – | Common Gateway Interface – used to exchange information with a server. |
| .chk | – | Data recovered after running Checkdisk. |
| .css | style sheet | Plain text file containing web page style preferences. |
| .csv | data | Comma Separated Value file – a way of presenting tabular data in a text file – usually viewed in MS Excel. |
| .dat | data file | Used by several applications. Not to be opened directly. |
| .dcr | media file | Macromedia (Now Adobe) Shockwave movie. |
| .dir | media file | Macromedia (Now Adobe) Director file – provides animation and interactivity. |
| .dll | dynamic link library | Software used by Windows to provide services to applications. |
| .doc | document | Microsoft Word file. |
| .docx | document | Microsoft Word 7, 10 file. |
| .dot | template | Microsoft Word template. |
| .dotx | template | Microsoft Word 7 template. |
| .drv | device driver | Used to control hardware – (old). |
| .dtd | text | Document type definition. |
| .exe | application | Self-extracting or executable file – run by double-clicking. |
| .faq | data file | Frequently Asked Questions – almost always a text file. |
| .fla | media | Macromedia (Now Adobe) Flash animation file – requires Shockwave. |
| .fnt | – | Font file. |
| .ftl | web page | Family Tree Legends Document. |
| .gif | image | Graphic in GIF format – open in web browser or graphics program. |
| .gz | application | Compressed archive file created by Gzip in the UNIX operating system. |
| .htm | text file | Hypertext document (same as .html). Open in a web browser – edit in any word-processor or text editor. |
| .ico | Windows icon | Open with an icon editor. |
| .ini | – | Initialisation file. |
| .jar | Java | Java compressed archive file. |
| .jav | Java | Cross platform programming language used to create complex interactive forms and special effects. |
| .jpg | image | Graphic in JPEG format (Joint Photographic Experts Group) View with web browser or image editing program. |
| .js | JavaScript | Part of web page used to create interactive effects such as mouse roll-overs and pop-up boxes. |
| .jso | – | Java server page. |
| .kbd | data file | Keyboard layout data. |
| .log | data file | Created by many applications – usually a text file – edit in any text editor. |
| .mht | single file web page | Web page dowload file. |
| .mid | audio | Audio file in MIDI format. |
| .mov | video | QuickTime movie – or view using IE. |
| .mp3 | audio | Audio file in MP3 format – CD-quality sound, with 10x compression. |
| .mpg | movie | Video movie in MPEG format (Motion Picture Experts Group). |
| .old | – | Backup file (generic). |
| application | Portable Document Format – requires Adobe Acrobat Reader. | |
| .pl | application | Perl source file – text file, editable in any text editor. |
| .png | image | Graphic in Portable Network Graphics format – can work on all platforms. |
| .ppt | application | Microsoft PowerPoint file – used for creating slides and overhead presentations. |
| .pptx | application | Microsoft PowerPoint 7 file – used for creating slides and overhead presentations. |
| .pub | – | Microsoft Publisher page template file. |
| .ram | audio | Real Audio file – open in browser with RealAudio plug-in. |
| .rtf | application | Rich Text Format - word-processor file with formatting codes. |
| .scr | screen saver | |
| .sig | signature | Appended to outgoing email messages – editable in text editor. |
| .swf | media | Macromedia (Now Adobe) Shockwave Flash animation movie. |
| .sys | – | DOS system file – device driver or hardware configuration info. |
| .tar | application | File archive created in the Unix operating system. |
| .tif | image | Tagged Image File format – graphic file – editable in graphics program. |
| .tmp | – | Temporary file – used by many programs. |
| .ttf | font | True Type Font file – view with fontview. |
| .txt | text | Contains only ASCII code – also called 'text file' – editable in any text editor. |
| .vlc | video clip | VideoLAN Client – movie clip – open with mplayer, or IE – see also .avi |
| .wav | audio | Sound file in Waveform format. |
| .wsz | graphics | Winamp skin – visual interface for audio control board. |
| .xls | application | Microsoft Excel worksheet file. |
| .xlsx | application | Microsoft Excel 7 worksheet file. |
| .xml | web page | Extensible markup language – a plain text file for web pages. |
| .zip | application | Compressed file – open with WinZip or PKZip. |
