lz4/lz4

Extremely Fast Compression algorithm

http://www.lz4.org

LZ4 - Extremely fast compression

LZ4 is a lossless compression algorithm, providing compression speed > 500 MB/s per core, scalable with multi-core CPUs. It features an extremely fast decoder, with speed in multiple GB/s per core, typically reaching RAM speed limits on multi-core systems.

Compression speed can be tuned dynamically, by selecting an "acceleration" factor which trades compression ratio for faster speed. On the other end, a high compression derivative, LZ4_HC, is also provided, trading CPU time for improved compression ratio. All versions feature the same decompression speed.

LZ4 is also compatible with dictionary compression, both at API and CLI (-D) levels. It can ingest any input file as dictionary, though only the final 64 KB are used. This capability can be combined with the Zstandard Dictionary Builder, in order to drastically improve compression performance on small files.

The LZ4 library is provided as open-source software using the BSD 2-Clause license. The lz4 command line utility is provided under the GPL-2.0-or-later license.

Benchmarks

The benchmark uses lzbench v2.4.1, from @inikep compiled with GCC v13.3.0 on Linux 64-bits (Ubuntu 24.04). The reference system uses a Core i7-9700K CPU. Benchmark evaluates the compression of reference Silesia Corpus in single-thread mode.

Compressor	Factor	Compression	Decompression
memcpy	1.000	13700 MB/s	13700 MB/s
LZ4 default (v1.11.0)	2.112	770 MB/s	4950 MB/s
LZO 2.10 -1	2.108	660 MB/s	800 MB/s
QuickLZ 1.5.1b7 -1	2.238	580 MB/s	780 MB/s
Snappy 1.3.1	2.090	520 MB/s	1350 MB/s
Zstandard 1.5.7 -1	2.896	510 MB/s	1570 MB/s
LZF v3.6	2.073	375 MB/s	920 MB/s
zlib-ng 2.3.3 -1	2.252	250 MB/s	555 MB/s
zlib deflate 1.3.2 -1	2.743	110 MB/s	410 MB/s
LZ4 HC -9 (v1.11.0)	2.717	40 MB/s	4800 MB/s
zlib deflate 1.3.2 -6	3.106	36 MB/s	430 MB/s

Installation

make
make install     # this command may require root permissions

LZ4's Makefile supports standard Makefile conventions, including staged installs, redirection, or command redefinition. It is compatible with parallel builds (-j#).

Alternative build systems (CMake, Meson, Visual Studio) are provided in build/.

Building LZ4 - Using vcpkg

You can download and install LZ4 using the vcpkg dependency manager:

git clone https://github.com/Microsoft/vcpkg.git
cd vcpkg
./bootstrap-vcpkg.sh
./vcpkg integrate install
./vcpkg install lz4

The LZ4 port in vcpkg is kept up to date by Microsoft team members and community contributors. If the version is out of date, please create an issue or pull request on the vcpkg repository.

Documentation

The raw LZ4 block compression format is detailed within lz4_Block_format.

Arbitrarily long files or data streams are compressed using multiple blocks, for streaming requirements. These blocks are organized into a frame, defined in lz4_Frame_format. Interoperable versions of LZ4 must also respect the frame format.

The library API is documented in its headers: lz4.h (block API), lz4hc.h (high compression) and lz4frame.h (frame API).

Other source versions

Beyond the C reference source, many contributors have created versions of lz4 in multiple languages (Java, C#, Python, Perl, Ruby, etc.). A list of known source ports is maintained on the LZ4 Homepage.

Packaging status

Most distributions are bundled with a package manager which allows easy installation of both the liblz4 library and the lz4 command line interface.

Special Thanks

Takayuki Matsuoka, aka @t-mat, for exceptional first-class support throughout the lifetime of this project

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