Compressing Files in Linux: gzip, bzip2, 7z, rar, and zip

File compression is a routine task in Linux administration. You’ll encounter several tools, each with different tradeoffs between compression ratio, speed, and compatibility. This guide covers the most common compression formats: gzip, bzip2, 7z, xz, and zip.

The examples below assume you’re compressing a directory called dir. Each tool supports compression level options — you can use maximum compression (slower, smaller files) or faster compression (larger files). The commands shown use maximum compression; strip those flags if you prefer speed over size.

gzip

Gzip is fast and widely available. It’s not ideal for archiving entire directory trees since it compresses a single stream, but it’s common for single files and as part of tar operations.

Compress:

gzip -r --best -c dir > ./dir.gz

Uncompress:

gunzip ./dir.gz
# or
gzip -d ./dir.gz

For faster compression without maximum compression:

gzip -r -c dir > ./dir.gz

bzip2

Bzip2 offers better compression than gzip but is slower. Pair it with tar for directory compression.

Compress:

tar -c dir | bzip2 --best -c > ./dir.tar.bz2

Uncompress:

tar xf ./dir.tar.bz2
# or
bunzip2 -c ./dir.tar.bz2 | tar x

Faster compression:

tar -c dir | bzip2 -c > ./dir.tar.bz2

xz

Xz provides excellent compression ratios, often better than bzip2, though it’s slower. It’s increasingly the default compression in many distributions.

Compress:

tar -cf - dir | xz --best -c > ./dir.tar.xz

Uncompress:

tar xf ./dir.tar.xz

Faster compression:

tar -cf - dir | xz -c > ./dir.tar.xz

You can also use tar’s built-in xz support:

tar -cJf ./dir.tar.xz dir

7z

7z delivers excellent compression but is slower and less portable. It’s useful when maximum compression matters and you control the decompression environment.

Compress:

7z a -t7z -m0=lzma2 -mx=9 -mfb=64 -md=32m -ms=on ./dir.7z dir

Uncompress:

7z x ./dir.7z

Faster compression:

7z a -t7z ./dir.7z dir

RAR

RAR is proprietary and less common on Linux. Most distributions don’t include it by default. If you must work with RAR files, install rar or unrar:

Compress (requires rar package):

rar a -m5 ./dir.rar dir

Uncompress:

unrar x ./dir.rar
# or
rar x ./dir.rar

Most scenarios benefit from open formats (gzip, bzip2, xz, 7z) instead. Use RAR primarily for compatibility with Windows environments.

ZIP

Zip is portable across Windows, macOS, and Linux. It’s slower than gzip but more compatible for cross-platform sharing.

Compress:

zip -r -9 ./dir.zip dir

Uncompress:

unzip ./dir.zip

Faster compression:

zip -r ./dir.zip dir

Exclude files during compression:

zip -r -9 ./dir.zip dir -x "*.log" "*.tmp"

Quick Comparison

Tool	Ratio	Speed	Portable	Use Case
gzip	Good	Fast	Excellent	Single files, streaming
bzip2	Better	Slow	Good	Archives, older systems
xz	Excellent	Slow	Good	Modern distributions, long-term storage
7z	Excellent	Slowest	Fair	Maximum compression, controlled environment
ZIP	Fair	Moderate	Excellent	Cross-platform sharing
RAR	Good	Moderate	Poor	Proprietary, legacy support

Practical Tips

Multithreaded compression: Gzip, bzip2, and xz all have multithreaded variants for faster compression on modern hardware:

# pigz (parallel gzip)
pigz -r -9 -c dir > ./dir.gz

# pbzip2 (parallel bzip2)
pbzip2 --best -c < file.txt > file.txt.bz2

# xz with multiple threads
xz --threads=4 --best file

Verify integrity: After decompression, verify the archive wasn’t corrupted:

gzip -t ./dir.gz
7z t ./dir.7z
unzip -t ./dir.zip

List contents without extracting:

tar -tzf ./dir.tar.gz
7z l ./dir.7z
unzip -l ./dir.zip

Remove source after compression: Safely delete the original only after verifying the compressed file:

tar -czf dir.tar.gz dir && rm -rf dir

For most Linux systems, xz provides the best balance of compression ratio and modern tool support. Use gzip for compatibility and speed, zip for cross-platform scenarios, and 7z when maximum compression is essential.