Computer file extensions - A

Updated: 01/31/2023 by Computer Hope

Below is a listing of each of the different file extensions that begin with the letter "A." If you are looking for a file extension that starts with a different letter, click the corresponding beginning letter below.

.A ADA program file or Unix library.
.A3W Macromedia Authorware 3.5 file.
.ABK Autobackup file used with CorelDRAW 6 and above.
.ABM 1.) Album for digital music, including songs.
2.) Album containing references to pictures in a digital music album.
.ABR Brush file for Adobe Photoshop.
.ACE WinAce compressed file.
.ACR File format for medical images.
.ACT Adobe Photoshop color table file.
.AD After Dark file or a Microsoft Access point file.
.ADF Adapter description files.
.ADM After Dark screen saver module.
.ADP Microsoft Access project.
.ADR After Dark randomizer or Opera browser bookmark backup.
.AI Adobe Illustrator file.
.AIF AIFF (Auto Interchange File Format) audio file.
.AIR Adobe AIR software installation file.
.ANI Windows animated mouse cursor file.
.ALX ActiveX layout file or BlackBerry application loader file.
.ANS ANSI (American National Standards Institute) text file.
.APK Android application package.
.ARC Short for archive, .ARC was an early compressed file format.
.ARJ Compressed file extracted and used with various compression utilities.
.ARK Short for archive, .ARK was an early compressed file format.
.AS Short for AppleSingle, .AS is a compressed file extracted and used with various compression utilities.
.ASC ASCII (American Standard Code for Information Interchange) text file.
.ASE 1.) Adobe Swatch Exchange file, used by Adobe InDesign and Adobe Illustrator.
2.) File created by Aseprite software, containing a sprite.
.ASF Sort for Advanced Streaming Format, file developed by Microsoft. The .ASF file is generally a movie player and can be open with software such as Windows Media Player.
.ASL Adobe Photoshop file containing style data, to be applied to layers or objects.
.ASP Microsoft Active Server Pages. To open these files, use your Internet browser.
.ASX Media playlist file, or file containing shortcuts to media files. Used by Windows Media Player and other media players.
.ATO Compaq Just Burn file.
.ATY 3D Topicscape association type after export to Windows.
.AU Sun and NeXT audio file.
.AVI Microsoft Windows movie file. See avi page for further information.
.AXX AxCrypt encrypted file.
.AZW An eBook formatted for a Kindle device.