The WMF (Windows Metafile) format is a Microsoft proprietary graphic format initially developed to be used with the Windows operating system. The first Windows Metafiles appeared in 1988 along with Windows version 2.0. Later, the WMF format gained support for both Linux and Macintosh operating systems. The Windows Metafile format specification was published by Microsoft with the release of Windows 3.1 in 1992 and was updated in 2006.

WMF files can store both bitmap and vector image data and may include a wide range of drawing operations such as commands for drawing rectangles, lines, circles and other more complex geometrical shapes. The WMF format is mainly used for storing vector images but can also contain raster graphics.

Initially, the WMF format was designed to act as a bridge format that enabled users to convert vector graphics to raster graphics and vice versa. As new cross-platform image formats were developed, the need for WMF files decreased and as a result the WMF file format was replaced by other formats such as JPEG or GIF. However, WMF files are still supported by a large number of applications.