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Google Earth saved working session file (.kmz)

.kmz file signature | application/octet-stream

zip file formatand formats based on it, such asEPUB,JAR,ODF,OOXML

Safe

Magic Bytes

Offset 0
50 4B 03 04 50 4B 05 06 50 4B 07 08

Sources: Wikipedia

All Known Signatures

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

Hex Signature Offset Sources
50 4B 03 04 50 4B 05 06 50 4B 07 08 0 Wikipedia
50 4B 03 04 0 Gary Kessler

Extension

.kmz

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .kmz files in Python

Python 
def is_kmz(file_path: str) -> bool:
    """Check if file is a valid KMZ by magic bytes."""
    signature = bytes([0x50, 0x4B, 0x03, 0x04, 0x50, 0x4B, 0x05, 0x06, 0x50, 0x4B, 0x07, 0x08])
    with open(file_path, "rb") as f:
        return f.read(12) == signature

How to validate .kmz files in Node.js

Node.js 
function isKMZ(buffer: Buffer): boolean {
  const signature = Buffer.from([0x50, 0x4B, 0x03, 0x04, 0x50, 0x4B, 0x05, 0x06, 0x50, 0x4B, 0x07, 0x08]);
  return buffer.subarray(0, 12).equals(signature);
}

How to validate .kmz files in Go

Go 
func IsKMZ(data []byte) bool {
    signature := []byte{0x50, 0x4B, 0x03, 0x04, 0x50, 0x4B, 0x05, 0x06, 0x50, 0x4B, 0x07, 0x08}
    if len(data) < 12 {
        return false
    }
    return bytes.Equal(data[:12], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .kmz file?

A .kmz file is a Google Earth saved working session file file. zip file formatand formats based on it, such asEPUB,JAR,ODF,OOXML

What are the magic bytes for .kmz files?

The magic bytes for Google Earth saved working session file files are 50 4B 03 04 50 4B 05 06 50 4B 07 08 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .kmz file?

To validate a .kmz file, read the first bytes of the file and compare them against the known magic bytes (50 4B 03 04 50 4B 05 06 50 4B 07 08) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .kmz files?

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

Is it safe to open .kmz files?

Google Earth saved working session file (.kmz) 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.