{
 "id": "cdx",
 "name": "CDX",
 "category": "archive",
 "identifiers": {
  "extensions": [
   "cdx"
  ],
  "mime": [
   "text/plain"
  ],
  "puid": [
   "fmt/869"
  ],
  "wikidata": [
   "Q47538013"
  ],
  "loc_fdd": [
   "fdd000590"
  ],
  "magic": [
   {
    "offset": 0,
    "hex": "2043445820",
    "notes": "CDX Archive Index variant 1"
   },
   {
    "offset": 0,
    "hex": "43445820",
    "notes": "CDX Archive Index variant 2"
   }
  ],
  "signatures": [
   {
    "name": "CDX Archive Index variant 1",
    "sequences": [
     {
      "position": "bof",
      "offset": 0,
      "pattern": "2043445820"
     }
    ]
   },
   {
    "name": "CDX Archive Index variant 2",
    "sequences": [
     {
      "position": "bof",
      "offset": 0,
      "pattern": "43445820"
     }
    ]
   }
  ]
 },
 "status": "readable",
 "summary": "A CDX file consists of individual lines of text, each of which summarizes a single web document. The first line in the file is a legend for interpreting the data, and the following lines contain the data for referencing the corresponding pages within the host. The CDX signatures use a field delimiter character which is assumed to be a space character, however please contact the PRONOM team should you encounter CDX index files where the delimiter is different.",
 "tools": [
  {
   "name": "Webrecorder Player",
   "url": "https://www.wikidata.org/wiki/Q61706497",
   "reads": true,
   "writes": false,
   "license": "Apache Software License 2.0",
   "open_source": true
  }
 ],
 "projects": [
  {
   "name": "File Formats Wiki",
   "url": "http://fileformats.archiveteam.org/wiki/CDX",
   "kind": "wiki"
  },
  {
   "name": "PRONOM fmt/869",
   "url": "https://www.nationalarchives.gov.uk/PRONOM/fmt/869",
   "kind": "format-doc"
  },
  {
   "name": "Wikidata Q47538013",
   "url": "https://www.wikidata.org/wiki/Q47538013",
   "kind": "wiki"
  }
 ],
 "provenance": {
  "sources": [
   "ffw",
   "pronom",
   "wikidata"
  ]
 },
 "updated": "2026-10-24",
 "aliases": [],
 "structure": [],
 "parsers": [],
 "conversions": [],
 "samples": [],
 "claims": [],
 "verification": []
}