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Microsoft Windows Imaging Format file (.wim)

.wim file signature | application/octet-stream

Microsoft Windows Imaging Format file

Safe

Magic Bytes

Offset 0
4D 53 57 49 4D 00 00 00 D0 00 00 00 00

Sources: Wikipedia

All Known Signatures

2 signature variants are documented for .wim files across multiple sources.

Hex Signature Offset Sources
4D 53 57 49 4D 00 00 00 D0 00 00 00 00 0 Wikipedia
4D 53 57 49 4D 0 Gary Kessler

Extension

.wim

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .wim files in Python

Python
def is_wim(file_path: str) -> bool:
    """Check if file is a valid WIM by magic bytes."""
    signature = bytes([0x4D, 0x53, 0x57, 0x49, 0x4D, 0x00, 0x00, 0x00, 0xD0, 0x00, 0x00, 0x00, 0x00])
    with open(file_path, "rb") as f:
        return f.read(13) == signature

How to validate .wim files in Node.js

Node.js
function isWIM(buffer: Buffer): boolean {
  const signature = Buffer.from([0x4D, 0x53, 0x57, 0x49, 0x4D, 0x00, 0x00, 0x00, 0xD0, 0x00, 0x00, 0x00, 0x00]);
  return buffer.subarray(0, 13).equals(signature);
}

How to validate .wim files in Go

Go
func IsWIM(data []byte) bool {
    signature := []byte{0x4D, 0x53, 0x57, 0x49, 0x4D, 0x00, 0x00, 0x00, 0xD0, 0x00, 0x00, 0x00, 0x00}
    if len(data) < 13 {
        return false
    }
    return bytes.Equal(data[:13], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .wim file?

A .wim file is a Microsoft Windows Imaging Format file file. Microsoft Windows Imaging Format file

What are the magic bytes for .wim files?

The magic bytes for Microsoft Windows Imaging Format file files are 4D 53 57 49 4D 00 00 00 D0 00 00 00 00 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .wim file?

To validate a .wim file, read the first bytes of the file and compare them against the known magic bytes (4D 53 57 49 4D 00 00 00 D0 00 00 00 00) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .wim files?

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

Is it safe to open .wim files?

Microsoft Windows Imaging Format file (.wim) 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.