What is the WMF file format?
.wmf is a vector image file developed by Microsoft, introduced with Windows 3.0 in 1990. Vector graphics are composed of objects and their geometric relations, in contrast to raster graphics which are made of a grid of pixels. The .wmf format also supports raster graphics, albeit in a limited manner - embedded bitmaps (DIBs) can appear alongside GDI drawing commands within the file.
Internally, the format records a sequence of 16-bit Windows GDI commands. The most common variant is the Placeable WMF (Aldus APM), prefixed with a 22-byte header identified by the magic bytes D7 CD C6 9A at offset 0.
The format never gained much popularity compared to other similar formats. It offered limited image scaling capabilities and was cumbersome to use in larger projects, partly because 16-bit signed coordinates cap precision to ±32,767 logical units. Microsoft replaced it with the 32-bit .emf (Enhanced Metafile) in 1993; a GZIP-compressed variant saves as .wmz.
Security & safety
RISK: MEDIUMA normal WMF contains drawing commands, not macros, so the picture content is passive. The real concern is parser exploits: the 2005-2006 Windows Metafile vulnerability abused the SETABORTPROC metafile record to execute arbitrary code just from viewing a crafted WMF, and GDI metafile parsing has had periodic CVEs since. Keep Windows and Office patched and be cautious with unsolicited .wmf files from unknown senders. A WMF inside an ordinary old Office document is almost always harmless clipart.
Format details
in a nutshellFULL NAMEWindows Metafileaka Windows Metafile Format, WMF picture
DEVELOPERMicrosoftsince 1990 (Windows 3.0); documented publicly as MS-WMF
CATEGORYVector Image Files
MIME TYPEimage/wmf
TYPE16-bit Windows GDI vector image - a recorded sequence of GDI drawing commands (can embed bitmaps)
STANDARDOpen · royalty-free
MAGIC BYTES · FILE SIGNATURE
OFFSET
00010203
HEX
D7CDC69A
ASCII
····
A Placeable WMF (the common form, Aldus APM header) starts with DWORD D7 CD C6 9A (0x9AC6CDD7) at offset 0, followed by a 22-byte placeable header, then the standard 18-byte WMF header. A bare (non-placeable) WMF instead begins with 01 00 09 00 (memory metafile) or 02 00 09 00 (disk metafile). The newer 32-bit successor EMF starts with 01 00 00 00 and ' EMF' at offset 40 - a different file type.
Programs that open WMF files
Windows5 apps
IrfanView
Free Opens WMF directly via Windows GDI; great for quick view and batch conversion to PNG/JPG. 
Inkscape
Open-source File > Open imports the WMF as editable vector paths; ideal to recolor/edit and export SVG. Free. 
LibreOffice Draw
Open-source File > Open the .wmf to view/edit the vectors and export PNG/SVG/PDF. Free. 
Microsoft Word / PowerPoint (Microsoft 365)
Paid Insert > Pictures > This Device > select the .wmf; Office renders it natively, and right-click > Save as Picture exports PNG/SVG/JPG. 
macOS3 apps
Adobe Illustrator
Paid File > Open imports the WMF as editable vector art (best effort; some GDI records may differ).
LibreOffice Draw
Open-source Best free macOS option - open the .wmf in Draw (its own WMF interpreter, no GDI needed) and export PNG/SVG/PDF. 
Linux3 apps
LibreOffice Draw
Open-source Open the .wmf in Draw to view/convert - the most reliable Linux option. Technical details
deep spec| File type | 16-bit Windows GDI vector metafile; stores a replayed sequence of GDI drawing commands |
| Encoding | Binary record stream, little-endian byte order |
| MIME type | `image/wmf`; alternatives: `image/x-wmf`, `application/x-msmetafile` |
| Magic bytes (Placeable WMF) | `D7 CD C6 9A` at offset 0 in the Placeable (Aldus APM) variant |
| Magic bytes (bare WMF) | `01 00 09 00` (memory metafile) or `02 00 09 00` (disk metafile) |
| File structure | Optional 22-byte Aldus APM header + 18-byte WMF header + GDI record sequence + EOF record |
| Coordinate precision | 16-bit signed integers, ±32,767 logical units per axis |
| Color depth | Device-dependent; GDI records use palette or RGB values; embedded DIBs support 1-24 bpp |
| Embedded bitmaps | Device-independent bitmaps (DIBs) can be included within the GDI record stream alongside vector records |
| Compression | None; GZIP-compressed variant is `.wmz` |
| Checksum | 16-bit XOR checksum field in the Aldus APM placeable header only |
| Successor format | `.emf` (Enhanced Metafile), 32-bit GDI replacement since Windows NT 3.1 (1993) |
| Platform support | Windows (native GDI); macOS and Linux via Inkscape, LibreOffice Draw, Adobe Illustrator |
| Security note | `SETABORTPROC` escape record vulnerability permitted arbitrary code execution; widely exploited in 2005-2006 |
| Released | 1990 (Windows 3.0); documented publicly as MS-WMF |
| Latest version | MS-WMF specification (format frozen; superseded by EMF) |
| Open standard | Yes · royalty-free |
| Specification | learn.microsoft.com |
WMF conversions
Possible
.WMF .PNGGUIDE
Yes - the fastest way is to open the WMF in IrfanView (Windows, free) and use File > Save As > PNG.
How to convert
.WMF .BMPGUIDE
Yes, WMF converts to BMP without issues; the fastest route is IrfanView (free) - open the file and use File >…
How to convert
.WMF .SVGGUIDE
Yes, WMF can be converted to SVG; the fastest free route on any platform is Inkscape or LibreOffice Draw.
How to convert
.WMF .EMFGUIDE
Yes - open the WMF in LibreOffice Draw (free) and use File > Export to save it as EMF.
How to convert
.WMF .EPSGUIDE
Yes, WMF can be converted to EPS - open the file in Inkscape or LibreOffice Draw and export.
How to convert
.WMF .JPGGUIDE
Yes, you can convert WMF to JPG - the fastest way on Windows is to open the file in IrfanView and use File →…
How to convert
.WMF .PDFGUIDE
Yes -- open the WMF in LibreOffice Draw (free) and use File > Export as PDF; vectors are preserved.
How to convert
.WMF .AIGUIDE
Yes, you can convert WMF to AI -- open the file in Adobe Illustrator (paid) or Inkscape (free) and save it as…
How to convert
.WMF .CDRGUIDE
Yes, you can convert WMF to CDR - open the WMF in CorelDRAW and save as .cdr; there is no other realistic…
How to convert
Not possible
Community Q&A
asked by usersNo questions yet - be the first to ask about WMF files.
Frequently asked questions
How do I open a WMF file?
On Windows, open it in free IrfanView/XnView, in Inkscape, or insert it into Word/PowerPoint (Insert > Pictures). On Mac/Linux use LibreOffice Draw or Inkscape (free). To edit the vectors, use Inkscape or Illustrator.
How do I convert WMF to SVG or PNG?
For SVG (editable vector), open the WMF in Inkscape or LibreOffice Draw and export SVG. For PNG, use IrfanView/XnView Save As, or export PNG from Inkscape/LibreOffice Draw at a high enough resolution.
What is the difference between WMF and EMF?
WMF is the older 16-bit Windows Metafile (since Windows 3.0, 1990); EMF is its 32-bit successor (since Windows NT 3.1, 1993) with more drawing commands, better precision and device independence. EMF is preferred; WMF is legacy.
What is WMZ?
WMZ is simply a WMF compressed with GZIP (like SVGZ vs SVG). Rename it to .wmf.gz and decompress with 7-Zip/gunzip to get the plain WMF back, losslessly.
Can I open a WMF file on a Mac?
Nothing built-in reads it well. Install LibreOffice (free) and open it in Draw, or use Inkscape - both have their own WMF interpreters and can export PNG/SVG/PDF. Adobe Illustrator also imports WMF.
Is a WMF a vector or raster image?
Usually vector - it stores drawing commands and scales - but WMF records can embed bitmaps, so some WMF files are effectively wrapped raster images.
Are WMF files dangerous?
Old WMF parsing had a serious code-execution flaw (2005-2006), so a crafted WMF could be risky on an unpatched system. On a patched Windows, ordinary WMF clipart is safe; just avoid opening unsolicited ones from unknown sources.
References
1Microsoft Open Specifications - MS-WMF: Windows Metafile Formatlearn.microsoft.com
2Wikipedia - Windows Metafileen.wikipedia.org
