ThumbnailCNC is a service that is installed on a computer running Windows Vista or newer operating system. After installation, all the CNC programs on your computer will be represented by a thumbnail (small picture) when browsing directories with Windows Explorer (Just as you see thumbnails of your pictures from your digital camera).


The service also includes a view for the Windows File Explorer preview feature. This view shows both the actual CNC program as text and an image reprecentation of the program's toolpaths. Different versions of Windows have the setting to display Preview in different locations. In Windows 10, you must first click the View tab in the File Explorer.

External programs

Visualization of files will not only be available in Windows File Explorer. It can be used in any application that uses standard dialogs to open and save files, as most windows programs do. The implementation of the service in external software is performed automatically by Windows no additional configuration is required. If the open file dialog in your favorite program for editing G-code or DNC system is similar to the one in Windows Notepad. Then there is a great chance that G-code visualization will be available in the program's file selector.

Codes that are supported:

  • Rapid traverse: G0, G00, FMAX, F9999
  • Linear movement: G1, G01, L
  • Circular movement: G2, G02, G3, G03, C, CC, DR+, DR
  • Drilling/Thread Cycle: G81, G74, G73, G83, G84, G82


By downloading and installing ThumbnailCNC you agree to our EULA which can be read by here