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LZ (.lz)

.lz file signature | application/x-lzip

lzipcompressed file[20]

Safe

Magic Bytes

Offset 0
4C 5A 49 50

Sources: Apache Tika, Wikipedia

Extension

.lz

MIME Type

application/x-lzip

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .lz files in Python

Python
def is_lz(file_path: str) -> bool:
    """Check if file is a valid LZ by magic bytes."""
    signature = bytes([0x4C, 0x5A, 0x49, 0x50])
    with open(file_path, "rb") as f:
        return f.read(4) == signature

How to validate .lz files in Node.js

Node.js
function isLZ(buffer: Buffer): boolean {
  const signature = Buffer.from([0x4C, 0x5A, 0x49, 0x50]);
  return buffer.subarray(0, 4).equals(signature);
}

How to validate .lz files in Go

Go
func IsLZ(data []byte) bool {
    signature := []byte{0x4C, 0x5A, 0x49, 0x50}
    if len(data) < 4 {
        return false
    }
    return bytes.Equal(data[:4], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .lz file?

A .lz file is a LZ file. lzipcompressed file[20]

What are the magic bytes for .lz files?

The magic bytes for LZ files are 4C 5A 49 50 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .lz file?

To validate a .lz file, read the first bytes of the file and compare them against the known magic bytes (4C 5A 49 50) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .lz files?

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

Is it safe to open .lz files?

LZ (.lz) 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.