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XZ archive file (.xz)

.xz file signature | application/x-xz

XZcompression utilityusingLZMA2compression

Safe

Magic Bytes

Offset 0
FD 37 7A 58 5A 00

Sources: Apache Tika, Wikipedia, Gary Kessler

Extension

.xz

MIME Type

application/x-xz

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .xz files in Python

Python
def is_xz(file_path: str) -> bool:
    """Check if file is a valid XZ by magic bytes."""
    signature = bytes([0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00])
    with open(file_path, "rb") as f:
        return f.read(6) == signature

How to validate .xz files in Node.js

Node.js
function isXZ(buffer: Buffer): boolean {
  const signature = Buffer.from([0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00]);
  return buffer.subarray(0, 6).equals(signature);
}

How to validate .xz files in Go

Go
func IsXZ(data []byte) bool {
    signature := []byte{0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00}
    if len(data) < 6 {
        return false
    }
    return bytes.Equal(data[:6], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .xz file?

A .xz file is a XZ archive file file. XZcompression utilityusingLZMA2compression

What are the magic bytes for .xz files?

The magic bytes for XZ archive file files are FD 37 7A 58 5A 00 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .xz file?

To validate a .xz file, read the first bytes of the file and compare them against the known magic bytes (FD 37 7A 58 5A 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 .xz files?

The primary MIME type for .xz files is application/x-xz.

Is it safe to open .xz files?

XZ archive file (.xz) 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.