FILE FORMAT GUIDE

GZIP Compressed File (.GZ): Meaning & Safe Handling

A GZ file contains one or more gzip members. Each member has a header, Deflate-compressed data and a trailer with CRC-32 and uncompressed size information.

Check supported header evidence locally. Identification is not file validation or a malware scan.

Analyze a file locally

Quick facts

Extension
.gz
Format
GZIP Compressed File
Category
archive
MIME type
application/gzip
Standard / developer
IETF
Open with
no reviewed opener

What is GZ?

The fixed 1F 8B bytes identify gzip and the method byte normally selects Deflate. Member concatenation is part of the format; the original filename and timestamp are optional metadata, not guaranteed facts.

  • Compress a byte stream for storage or transfer

How to open GZ

No named opener is asserted. Inspect only as inert text in a controlled workflow; do not execute scripts or follow shortcut targets.

Technical details

Signature
1F 8B
Encoding
Not reviewed
Container
Series of gzip members
Compression
Deflate

RFC 1952 GZIP File Format

Things to check

  • Gzip does not provide random access, archive directory semantics or encryption.

Sources & review

Fact review: 2026-09-19. Unknown fields are not inferred from the file extension.