7-Zip vs Zstandard

7-Zip is a file archiver for Windows, Linux, and macOS, offered at free with no registration or payment required. It creates and extracts 7z, XZ, BZIP2, GZIP, TAR, ZIP, and WIM archives, and can extract additional formats such as RAR, ISO, and VHDX. The 7z format uses LZMA and LZMA2 compression, and AES-256 encryption is available for 7z and ZIP files. Other listed capabilities include split archives, archive repair, portable use, and command-line tools. The Windows version includes Shell integration, a file manager, a command-line version, and a FAR Manager plugin. The software is open source; most code is under the GNU LGPL, with some under BSD licenses and an unRAR restriction applying to some parts. The maker says it can be used in commercial organizations without payment. It is localized in 87 languages. Developers can use the LZMA SDK, which includes documentation, samples, headers, libraries, and tools for applications using LZMA compression.

Zstandard is a lossless compression algorithm for real-time workloads, with controls that let users shift compression speed and ratio in small increments. Its reference implementation includes a C library and a command-line utility that creates and decodes .zst, .gz, .xz, and .lz4 files. The format is stable and documented in RFC 8878; the implementation is available under BSD or GPLv2. For small, related samples, training can produce a data-specific dictionary to improve compression. The same dictionary must be present for both compression and decompression, and the samples need to be correlated; there is no universal dictionary. The project documents builds with Make, CMake, Meson, Visual Studio, Buck, and Bazel, plus installation using vcpkg and Conan. Community bindings and ports are listed for languages including Python, Rust, Java, C#, JavaScript, Go, PHP, and Swift. Zstandard is free, with a free plan, and supports Linux, Windows, and macOS.