The File Extensions Database


.$AC File Extension

  • Developer by: Autodesk, Inc.
  • Category: 3d graphics, CAD-CAM-CAE Files

What is an .$AC file?

.$AC is Autodesk AutoCAD autosave

The $ac file extension is associated with Autodesk AutoCAD, a popular CAD modeling software for Windows and Mac.

The $ac file contains autosaved CAD drawing. It is used as a backup of AutoCAD project against application, or computer crash. After the project is finally saved by user, the autosave file will be deleted.


How to open:

Use AutoCAD to open *.$ac CAD autosave files.

How to convert:

Restore data from *.$ac files with AutoCAD and save them to other CAD formats.

How to solve problems with $AC files

  • Associate the $AC file extension with the correct application. On :
    Windows: Right click on any $AC file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *.$AC files". Mac: Right click (or Ctrl-click) the $AC file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
  • Update your software that should actually open .$AC is Autodesk AutoCAD autosave. Because only the current version supports the latest $AC file format. Search, therefore, e.g. on the Autodesk, Inc. manufacturer website after an available .$AC is Autodesk AutoCAD autosave update.
  • To make sure that your $AC file is not corrupted or virus-infected, get the file again and scan it with antivirus software.