Zstandard

Zstandard (commonly abbreviated as zstd) is a fast real-time compression algorithm developed by Facebook (Meta), with the goal of providing a compression ratio comparable to DEFLATE/zlib while offering significantly faster compression and decompression speeds. Created by Yann Collet (who also created LZ4 and XXHash), Zstandard was first released in 2015 and has since become one of the most widely adopted general-purpose compression algorithms, integrated into the Linux kernel, major package managers (APT, RPM, Pacman), database systems (RocksDB, Cassandra, MySQL), file systems (BTRFS, OpenZFS), container formats, and countless other software systems. The algorithm delivers compression ratios that rival or exceed those of gzip and zlib while being 3 to 5 times faster on the same hardware for compression and even faster for decompression. Key features include: a wide range of compression levels (from 1 to 22, with level 3 as the default), where higher levels achieve better ratios at the cost of speed; extremely fast decompression regardless of compression level, with typical throughput of 1 to 2 GB per second on modern hardware; support for training custom dictionaries for small files (files smaller than 100KB), where standard algorithms perform poorly due to insufficient data for building frequency tables, but Zstandard's dictionary mode can achieve compression ratios 3 to 10 times better than gzip for such files; a long-distance matching mode (LDM) for large files (over 100MB) that achieves near-LZMA compression ratios; streaming API for compressing data without loading the entire input into memory; support for frames and skippable frames for robust data framing; checksums (XXHash64) for data integrity verification; and backward-compatible format versions ensuring old compressed data remains decodable with newer library versions. As of 2026, Zstandard has over 9,000 GitHub stars.