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VMware 4 Virtual Disk description file (.vmdk)

.vmdk file signature | application/octet-stream

VMware 3 Virtual Disk (portion of a split disk) file

Safe

Magic Bytes

Offset 0
4B 44 4D

Sources: Wikipedia, Gary Kessler

All Known Signatures

4 signature variants are documented for .vmdk files across multiple sources.

Hex Signature Offset Sources
4B 44 4D 0 Wikipedia, Gary Kessler
23 20 44 69 73 6B 20 44 65 73 63 72 69 70 74 6F 0 Wikipedia, Gary Kessler
43 4F 57 44 0 Gary Kessler
4B 44 4D 56 0 Gary Kessler

Extension

.vmdk

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .vmdk files in Python

Python
def is_vmdk(file_path: str) -> bool:
    """Check if file is a valid VMDK by magic bytes."""
    signature = bytes([0x4B, 0x44, 0x4D])
    with open(file_path, "rb") as f:
        return f.read(3) == signature

How to validate .vmdk files in Node.js

Node.js
function isVMDK(buffer: Buffer): boolean {
  const signature = Buffer.from([0x4B, 0x44, 0x4D]);
  return buffer.subarray(0, 3).equals(signature);
}

How to validate .vmdk files in Go

Go
func IsVMDK(data []byte) bool {
    signature := []byte{0x4B, 0x44, 0x4D}
    if len(data) < 3 {
        return false
    }
    return bytes.Equal(data[:3], signature)
}

API Endpoint

GET /api/v1/vmdk
curl https://filesignature.org/api/v1/vmdk

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .vmdk file?

A .vmdk file is a VMware 4 Virtual Disk description file file. VMware 3 Virtual Disk (portion of a split disk) file

What are the magic bytes for .vmdk files?

The magic bytes for VMware 4 Virtual Disk description file files are 4B 44 4D at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .vmdk file?

To validate a .vmdk file, read the first bytes of the file and compare them against the known magic bytes (4B 44 4D) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .vmdk files?

There is no officially registered MIME type for .vmdk files. Systems typically use application/octet-stream as a generic fallback when handling this format.

Is it safe to open .vmdk files?

VMware 4 Virtual Disk description file (.vmdk) files are generally safe to open. They are classified as low risk because they primarily contain data rather than executable code. However, always ensure files come from a trusted source.