What Is a ZSTD File and Why Does Mac Not Open It?
ZSTD files use the Zstandard compression algorithm, which was designed by Yann Collet at Facebook for real time compression workloads. Zstandard achieves decompression speeds several times faster than gzip while maintaining comparable compression ratios. macOS Archive Utility does not recognize the .zst extension and cannot decompress Zstandard data. Double clicking a .zst file in Finder shows a "no compatible application" error. UnFox includes libzstd compiled into its extraction engine, enabling native Zstandard decompression on both Intel and Apple Silicon Macs.
How Do You Decompress a ZSTD File on Mac?
Drag the .zst file onto UnFox or open it through the File menu with Cmd+O. UnFox detects the Zstandard compression header and decompresses the file to your chosen destination. A progress bar tracks decompression in real time. ZSTD files are single file compressions, so the output is a single decompressed file. For TAR.ZSTD archives that bundle multiple files, UnFox handles the compound format automatically by decompressing the Zstandard layer and then extracting the TAR contents.
How Does ZSTD Compare to GZIP and LZ4?
Zstandard occupies a middle ground between gzip and LZ4 in the compression speed spectrum. LZ4 decompresses faster but produces larger output files. Gzip compresses more aggressively but decompresses slower. Zstandard offers configurable compression levels from 1 to 22, allowing users to trade compression ratio for speed. At its fastest settings, Zstandard matches LZ4 decompression speed. At its highest settings, it approaches the compression ratio of LZMA. UnFox decompresses ZSTD files at all compression levels without any configuration.
ZSTD is one of 36 formats UnFox supports, including related compression types like LZ4, GZIP, LZMA, and XZ. all supported archive and compression formats for Mac.
UnFox provides drag and drop decompression, real time progress tracking, and automatic compound format detection. archive extraction features for Mac, iPhone, and iPad.