Compressed archive file (.lzh)

.lzh file signature | application/x-lzh-compressed

LZH is a compressed archive file format associated with the Lempel-Ziv-Huffman family and originally developed by Haruyasu Yoshizaki for the LHarc archiver. It was used to distribute software, documents, and bundled files on Unix and Japanese systems, and some tools still extract it today. As a legacy format, it is largely obsolete, but archives can still appear in older software collections and should be handled cautiously from untrusted sources.

Safe

Magic Bytes

Offset 2


              2D 6C 68 30 2D

Sources: Wikipedia

All Known Signatures

3 signature variants are documented for .lzh files across multiple sources.

Hex Signature	Offset	Sources
2D 6C 68 30 2D	2	Wikipedia
2D 6C 68 35 2D	2	Wikipedia
2D 6C 68	2	Gary Kessler

Extension

.lzh

MIME Type

application/x-lzh-compressed

Byte Offset

Risk Level

Safe

Validation Code

How to validate .lzh files in Python

Python

def is_lzh(file_path: str) -> bool:
    """Check if file is a valid LZH by magic bytes at offset 2."""
    signature = bytes([0x2D, 0x6C, 0x68, 0x30, 0x2D])
    with open(file_path, "rb") as f:
        f.seek(2)
        return f.read(5) == signature

How to validate .lzh files in Node.js

Node.js

function isLZH(buffer: Buffer): boolean {
  const signature = Buffer.from([0x2D, 0x6C, 0x68, 0x30, 0x2D]);
  if (buffer.length < 7) return false;
  return buffer.subarray(2, 7).equals(signature);
}

How to validate .lzh files in Go

func IsLZH(data []byte) bool {
    signature := []byte{0x2D, 0x6C, 0x68, 0x30, 0x2D}
    if len(data) < 7 {
        return false
    }
    return bytes.Equal(data[2:7], signature)
}

API Endpoint

GET /api/v1/lzh


              curl https://filesignature.org/api/v1/lzh

See the full API documentation for all endpoints and parameters.

Related Formats

.7z .ace .arj .bz .bz2 .cab

Frequently Asked Questions

What is a .lzh file?

A .lzh file is a Compressed archive file file. LZH is a compressed archive file format associated with the Lempel-Ziv-Huffman family and originally developed by Haruyasu Yoshizaki for the LHarc archiver. It was used to distribute software, documents, and bundled files on Unix and Japanese systems, and some tools still extract it today. As a legacy format, it is largely obsolete, but archives can still appear in older software collections and should be handled cautiously from untrusted sources.

What are the magic bytes for .lzh files?

The magic bytes for Compressed archive file files are 2D 6C 68 30 2D at byte offset 2. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .lzh file?

To validate a .lzh file, read the first bytes of the file and compare them against the known magic bytes (2D 6C 68 30 2D) at offset 2. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .lzh files?

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

Is it safe to open .lzh files?

Compressed archive file (.lzh) 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.