X-Windows dump file
File type: Miscellaneous file
Files with the xdm file extension are legacy dump files for the X Window System. They contain a captured X display rather than an ordinary application document.
File type category:
Miscellaneous file
Date updated: October 30, 2026
The xdm file extension identifies an X-Windows dump file associated with the X Window System, the graphical environment used mainly on Unix and other Unix-like platforms. The file contains data representing the contents of an X display.
This is an old format and is no longer commonly used. The recorded MIME type is application/x-xdma.
On a Unix-like system with the X Window System installed, try opening the file with the xwud utility, which displays X Window dump data. The extension may not be recognized automatically, so the file might need to be selected or supplied to the utility explicitly.
There is no widely used standalone conversion process for this legacy format. If xwud can display the file, the displayed image can be captured or exported through an image utility available on the X Window System.
Englishimage/x-xwindowdump