gzip / gunzip / zcat

Updated

July 31, 2026

Overview

gzip compresses single files with the DEFLATE algorithm (.gz). For multi-file archives, combine with tar. Prefer zstd for better speed/ratio on modern systems when available.

Syntax

gzip [options] [file...]
gunzip [options] [file...]
zcat file.gz

Common Options

Option	Description
`-k`	Keep original (GNU)
`-d`	Decompress
`-c`	Write to stdout
`-#`	Level 1–9 (fast–best)
`-t`	Test integrity
`-n` / `-N`	Strip / keep name+time in header
`-r`	Recursive (careful)
`-v`	Verbose

Examples with Explanations

gzip large.log                 # → large.log.gz, removes original
gzip -k large.log              # keep original
gzip -d large.log.gz
gunzip large.log.gz
zcat large.log.gz | less
gzip -c file > file.gz         # keep original via stdout
tar -czf a.tgz dir/            # tar+gzip

Level tradeoff

gzip -1 fast.log
gzip -9 slow-but-small.log