{
 "id": "compress-unix",
 "name": "Compress (Unix)",
 "category": "archive",
 "identifiers": {
  "extensions": [
   "z"
  ],
  "mime": [
   "application/x-compress"
  ],
  "puid": [
   "fmt/1671"
  ],
  "wikidata": [
   "Q29209269"
  ],
  "magic": [
   {
    "offset": 0,
    "hex": "1f9d",
    "notes": "File Formats Wiki"
   },
   {
    "offset": 0,
    "hex": "1f9d90",
    "notes": "Z Compressed Data"
   }
  ],
  "signatures": [
   {
    "name": "Z Compressed Data",
    "sequences": [
     {
      "position": "bof",
      "offset": 0,
      "pattern": "1f9d90"
     }
    ]
   }
  ]
 },
 "status": "writable",
 "summary": "Z Compressed Data are files that have been compressed by Unix's shell compression program, compress. The compress software was developed by Spencer Thomas in 1984 and uses LZW algorithm. The format has lossless data, it can be compressed and decompressed using the Unix and Linux operating systems.",
 "tools": [
  {
   "name": "7-Zip (WebAssembly)",
   "url": "https://github.com/use-strict/7z-wasm",
   "license": "LGPL-2.1-or-later (unRAR restriction)",
   "open_source": true,
   "reads": true,
   "writes": false
  },
  {
   "name": "Archive Utility",
   "url": "https://www.wikidata.org/wiki/Q963462",
   "reads": true,
   "writes": false
  },
  {
   "name": "B1 Free Archiver",
   "url": "http://www.b1.org/",
   "reads": true,
   "writes": false,
   "license": "proprietary license"
  },
  {
   "name": "compress",
   "url": "https://www.wikidata.org/wiki/Q291486",
   "reads": true,
   "writes": true
  },
  {
   "name": "libarchive",
   "url": "https://libarchive.org/",
   "reads": true,
   "writes": true,
   "license": "2-clause BSD License",
   "open_source": true
  },
  {
   "name": "Q215051",
   "url": "https://7-zip.org",
   "reads": true,
   "writes": false,
   "license": "GNU Lesser General Public License",
   "open_source": true
  },
  {
   "name": "WinZip",
   "url": "https://www.winzip.com/",
   "reads": true,
   "writes": false,
   "license": "shareware"
  },
  {
   "name": "Zipeg",
   "url": "http://www.zipeg.com/",
   "reads": true,
   "writes": false,
   "license": "BSD licenses",
   "open_source": true
  }
 ],
 "projects": [
  {
   "name": "File Formats Wiki",
   "url": "http://fileformats.archiveteam.org/wiki/Compress_(Unix)",
   "kind": "wiki"
  },
  {
   "name": "PRONOM fmt/1671",
   "url": "https://www.nationalarchives.gov.uk/PRONOM/fmt/1671",
   "kind": "format-doc"
  },
  {
   "name": "Wikidata Q29209269",
   "url": "https://www.wikidata.org/wiki/Q29209269",
   "kind": "wiki"
  }
 ],
 "provenance": {
  "sources": [
   "engines",
   "ffw",
   "pronom",
   "wikidata"
  ]
 },
 "updated": "2026-10-25",
 "conversions": [
  {
   "to": "zip",
   "tool": "7-Zip (WebAssembly)",
   "command": "In the browser at https://openformatdb.org/convert/, or convert_file in the OpenFormatDB MCP server",
   "fidelity": "lossless",
   "losses": "Files are kept; archive comments, permissions or encryption may not be.",
   "url": "https://openformatdb.org/convert/",
   "engine": "7zip"
  },
  {
   "to": "7z",
   "tool": "7-Zip (WebAssembly)",
   "command": "In the browser at https://openformatdb.org/convert/, or convert_file in the OpenFormatDB MCP server",
   "fidelity": "lossless",
   "losses": "Files are kept; archive comments, permissions or encryption may not be.",
   "url": "https://openformatdb.org/convert/",
   "engine": "7zip"
  },
  {
   "to": "tape-archive",
   "tool": "7-Zip (WebAssembly)",
   "command": "In the browser at https://openformatdb.org/convert/, or convert_file in the OpenFormatDB MCP server",
   "fidelity": "lossless",
   "losses": "Files are kept; archive comments, permissions or encryption may not be.",
   "url": "https://openformatdb.org/convert/",
   "engine": "7zip"
  }
 ],
 "aliases": [],
 "structure": [],
 "parsers": [],
 "samples": [],
 "claims": [],
 "verification": []
}