File Type Generic IconUnknown File
File Format Standard
Usage Open manually
Rank ★ ☆ ☆  Uncommon

UNK is short for "unknown." Therefore, a file with an ".unk" file extension is an unknown file. The UNK extension is simply a placeholder for the appropriate file extension.

If an UNK file contains textual data, the contents of the file may be viewed by opening the file in a text editor. However, if the file contains binary data, it may need to be opened by the associated program.

If you have an idea what the file type may be, you can try changing the UNK extension to the appropriate extension. Then double-click the file to see if it opens with the corresponding program. However, you should not open an UNK file received from an unknown source, as the file could contain malicious code, such as malware or a virus.

Unknown files may also have an .UNKNOWN file extension.

Open With

IconOriginal program that created the file

Updated April 23, 2010
Information from the PC File Extensions Reference