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Zstandard
What it is
Zstandard is a free, lossless compression algorithm for real-time scenarios. It aims for zlib-level speed with better compression ratios, and lets users adjust the balance between compression speed and ratio in small increments. Decompression speed remains roughly similar across those settings. For small, related data samples, training can create a data-specific dictionary to improve compression; the samples must be correlated, and the matching dictionary is needed for both compression and decompression. The reference implementation includes a C library and command-line utility for creating and decoding .zst, .gz, .xz, and .lz4 files. The format is stable and documented in RFC 8878, and the implementation is dual-licensed under BSD or GPLv2. Documented build and integration options include Make, CMake, Meson, Visual Studio, Buck, and Bazel, with vcpkg and Conan installation. Community-provided bindings and ports include Python, Rust, Java, C#, JavaScript, Go, PHP, and Swift. Zstandard supports Linux, Windows, and macOS.
For and against
For
- Free, lossless compression
- Configurable speed and compression-ratio trade-off
- C library and command-line utility included
- Supports Linux, Windows, and macOS
- Stable format documented in RFC 8878
Against
- No archive encryption
- No archive repair
- Dictionary compression requires a matching dictionary
- Dictionary training is not universal
The verdict
Zstandard provides a library and command-line option for lossless compression, with adjustable compression settings and dictionary support for suitable data. It does not provide archive encryption or repair.
Who it suits
Zstandard suits developers and operators who need configurable lossless compression in applications or command-line workflows. Its dictionary mode is aimed at families of small, correlated samples.
Plans and prices
Zstandard
Open-source reference library and command-line utility · BSD or GPLv2 license
Read 8 Oct 2026 · github.com
On the record
- API
- The API offers simple methods first and introduces more parameters and control for advanced use.facebook.github.io · read 8 Oct 2026
- Build and package integrations
- The project documents builds with Make, CMake, Meson, Visual Studio, Buck, and Bazel, and installation through vcpkg and Conan.github.com · read 8 Oct 2026
- Build integrations
- The repository documents builds or integration through Make, CMake, Meson, vcpkg, Conan, Visual Studio, Buck, and Bazel.github.com · read 8 Oct 2026
- Compression controls
- The compression speed and ratio trade-off is configurable in small increments, and decompression speed remains roughly similar across settings.github.com · read 8 Oct 2026
- Dictionary compression
- A training mode builds a dictionary from sample files to improve compression of small, related data; a matching dictionary must be loaded for compression and decompression.github.com · read 8 Oct 2026
- Format
- The Zstandard format is stable, documented in RFC 8878, and has multiple independent implementations.github.com · read 8 Oct 2026
- Language bindings
- The homepage lists community-provided bindings and ports for languages including Python, Rust, Java, C#, JavaScript, Go, PHP, and Swift.facebook.github.io · read 8 Oct 2026
- Latest listed release
- The GitHub releases page lists Zstandard v1.5.7 as the latest release.github.com · read 8 Oct 2026
- Library and CLI
- The reference implementation provides a C library and a command-line utility that can produce and decode .zst, .gz, .xz, and .lz4 files.github.com · read 8 Oct 2026
- License
- The reference implementation is dual-licensed under BSD or GPLv2.github.com · read 8 Oct 2026
- Platform builds
- The project documents Windows builds and CMake Universal2 builds for Apple Silicon and Intel Macs.github.com · read 8 Oct 2026
- Purpose
- Zstandard is a fast, lossless compression algorithm for real-time scenarios, targeting zlib-level speed with better compression ratios.github.com · read 8 Oct 2026
- Security reporting
- The project asks reporters to submit security issues through Meta's Bug Bounty program rather than public GitHub issues or pull requests.github.com · read 8 Oct 2026
- Security testing
- The project says it is continuously fuzzed for security issues by Google’s OSS-Fuzz program.github.com · read 8 Oct 2026
- Small-data constraint
- Dictionary training works when a family of small samples is correlated, and the project says there is no universal dictionary.github.com · read 8 Oct 2026
- Small-data dictionaries
- Training on sample files creates a data-specific dictionary that can improve compression of small, correlated data samples.github.com · read 8 Oct 2026
- Speed and ratio controls
- Compression speed and ratio can be adjusted in small increments, while decompression speed remains roughly similar across settings.github.com · read 8 Oct 2026
- Use at scale
- The project says Zstandard is deployed within Meta and other large cloud infrastructures to compress data in various formats and use cases.github.com · read 8 Oct 2026
