File extension
.wmf
Windows Metafile Format
.wmf files are Windows Metafiles: a vector graphics format that stores a sequence of Windows GDI drawing commands, used for clip art and scalable graphics in older Windows applications.
Known meanings
Formats and reference material for .wmf
Details
Format notes
Windows Metafile (WMF)
WMF is a graphics format native to Microsoft Windows that stores an image as a recorded list of Graphics Device Interface (GDI) drawing commands — move to a point, draw a line, select a pen or brush, output text — rather than as a grid of pixels. Because it replays drawing operations, a metafile can represent vector artwork that scales, which is why WMF was the standard format for Office clip art and for exchanging drawings between older Windows programs.
WMF is a 16-bit format reflecting its origins in early Windows. A standalone WMF
intended for interchange usually has a “placeable” header (the Aldus/APM header,
magic D7 CD C6 9A) that adds a bounding rectangle and unit information the base
format lacks. Its 32-bit successor, the Enhanced Metafile (EMF), is generally
preferred for newer work.
Status And Security Notes
WMF is a legacy format, still recognized by Windows and many graphics tools but rarely chosen for new content. It carries notable security history: because metafile records could invoke device functions, WMF handling was the basis of serious Windows exploits (notably the SETABORTPROC/Escape vulnerability). Software that renders untrusted metafiles should use hardened, updated code and disable the ability of records to invoke arbitrary callbacks.
Preservation Notes
For preservation, converting WMF artwork to a modern vector format such as SVG (or EMF within Windows workflows) while retaining the original is advisable, since faithful rendering depends on Windows GDI semantics and available fonts.
Further Reading
- [MS-WMF] Windows Metafile Format:
https://learn.microsoft.com/openspecs/windows_protocols/ms-wmf/