lz4

extremely fast lossless compression algorithm

TLDR

Compress file

$ lz4 [file]

Decompress file

$ lz4 -d [file.lz4]

Compress with high compression

$ lz4 -9 [file]

Compress keeping original

$ lz4 -k [file]

Compress to stdout

$ lz4 -c [file] > [file.lz4]

Test compressed file

$ lz4 -t [file.lz4]

Compress with fastest speed

$ lz4 -1 [file]

Decompress to stdout

$ lz4 -dc [file.lz4]

SYNOPSIS

lz4 [-d] [-k] [-# level] [-c] [options] [input] [output]

LZ4 is an extremely fast lossless compression algorithm. It prioritizes speed over compression ratio, making it ideal for real-time compression scenarios.Compression speeds can exceed 500 MB/s per core, with decompression even faster at over 1 GB/s. This makes LZ4 suitable for scenarios where speed matters more than file size.Higher compression levels (up to 12) trade speed for better ratios. Level 1 is fastest, default is 1. The HC (high compression) mode provides better ratios at slower speeds.Block size affects both speed and ratio. Larger blocks improve compression but use more memory. The default 4MB block balances performance and memory usage.LZ4 is widely used in databases (MySQL, PostgreSQL), filesystems (ZFS, Btrfs), and real-time applications. The frame format includes checksums for integrity verification.

PARAMETERS

-d, --decompress

Decompress.

-z, --compress

Compress (default).

-k, --keep

Keep source file.

-c, --stdout

Write to stdout.

-# (1-12)

Compression level (1=fastest, 12=best).

-f, --force

Overwrite without prompt.

-t, --test

Test compressed file integrity.

-l, --list

List information about .lz4 files.

-m

Multiple files mode.

-r

Recursive mode.

-B#

Block size (4-7, default 7=4MB).

--content-size

Store original size in header.

-v, --verbose

Verbose mode.

-q, --quiet

Suppress warnings.

--rm

Remove source file after operation.

INSTALL

sudo apt install lz4

sudo dnf install lz4

sudo pacman -S lz4

sudo apk add lz4

sudo zypper install lz4

brew install lz4

nix profile install nixpkgs#lz4

CAVEATS

Lower compression ratio than gzip/zstd. Not suitable when size is critical. Large blocks use more memory. Not all systems have lz4 installed by default. Frame format differs from raw LZ4 blocks.

HISTORY

LZ4 was developed by Yann Collet starting around 2011. It was designed to be the fastest compression algorithm available while maintaining reasonable compression ratios. The algorithm and implementation are BSD-licensed, enabling widespread adoption in various projects.

lz4