Enhanced Metafile file signature
Magic number at offset 40 · EMF
An Enhanced Metafile carries the record signature ' EMF' (20 45 4D 46) at offset 40 in its header. The first record type 0x00000001 sits at offset 0.
What this magic number means
A magic number is a short, fixed run of bytes at a known position that tells a program what a file really is, no matter what the filename says. If a file contains, at offset 40, the bytes 20 45 4D 46 (the text EMF), it is a Enhanced Metafile file.
Formats that use the 20 45 4D 46 signature
These file types in our database carry this signature:
How to check a file's signature
You can read the first bytes of any file yourself. The magic bytes are shown in hex, the same way this page lists them.
Linux & macOS
- xxd -s 40 -l 4 example.emf
- hexdump -C -s 40 -n 4 example.emf
- file example.emf
Windows (PowerShell)
- Format-Hex -Path example.emf -Count 44
Python
- f=open("example.emf","rb");f.seek(40);f.read(4).hex()
In your browser
- Drop the file into the WhatFileType identifier, which reads the signature without uploading it.
Frequently asked questions
What is the Enhanced Metafile file signature?
Enhanced Metafile files carry, at offset 40, the hex bytes 20 45 4D 46 ( EMF in ASCII). This magic number identifies the format regardless of the file's name or extension.
How do I check a file's magic number?
Open the file in a hex editor, or run a command such as xxd -l 44 example.emf on Linux or macOS, or Format-Hex -Path example.emf -Count 44 in Windows PowerShell, and read the first bytes.
Can a file fake the Enhanced Metafile signature?
Renaming a file does not change its bytes, so the extension can lie but the signature usually cannot. A genuine Enhanced Metafile file has these exact bytes; a file with the wrong bytes is not really Enhanced Metafile, whatever its name says.