{
  "id": "xlsx",
  "handle": "xlsx",
  "canonicalUrl": "https://bestskillsforclaude.com/en/skills/xlsx",
  "language": "en",
  "alternates": {
    "en": "https://bestskillsforclaude.com/en/skills/xlsx",
    "es": "https://bestskillsforclaude.com/es/skills/xlsx",
    "pt-BR": "https://bestskillsforclaude.com/pt-br/skills/xlsx",
    "ja": "https://bestskillsforclaude.com/ja/skills/xlsx"
  },
  "category": {
    "id": "document-work",
    "name": "Document work"
  },
  "publisher": {
    "name": "Anthropic",
    "url": "https://github.com/anthropics"
  },
  "source": "https://github.com/anthropics/skills/tree/main/skills/xlsx",
  "documentation": null,
  "licenseAsStated": "Source available, not open source",
  "runtime": "Claude apps and Claude Code",
  "lastReviewed": "2026-08-05",
  "headline": "When is the xlsx skill worth loading?",
  "summary": "For anything where the formulas have to recalculate on the recipient's machine.",
  "verdict": "The xlsx skill lets Claude produce and edit real Excel workbooks, with multiple sheets, formulas and formatting, rather than printing a table into the chat. Load it when someone will open the file in Excel or Sheets and keep working in it. If the data is going into a database or a script, ask for CSV or JSON instead.",
  "bestFor": "Budgets, models, trackers and reports where the recipient needs live formulas, not a static table.",
  "skipIf": "The numbers are being consumed by code, where a spreadsheet adds a parsing problem instead of solving one.",
  "keyTakeaways": [
    "Formulas are written as formulas, so the workbook stays useful after Claude hands it over.",
    "It can read an existing workbook, which is what makes bulk edits and re-formatting practical.",
    "Say which cells are inputs. Without that, everything tends to arrive as hard coded values.",
    "It is a spreadsheet builder, not a data source. Wrong numbers in, wrong numbers out."
  ],
  "quickStart": [
    "Install the document skills from anthropics/skills, or use a surface where they ship already enabled.",
    "Describe the workbook by sheet: what each tab holds, which cells are inputs and which are calculated.",
    "Open the file and change one input, to confirm the formulas recalculate the way you expected."
  ],
  "sections": [
    {
      "heading": "What it changes in practice",
      "paragraphs": [
        "A chat answer containing a table is a picture of a calculation. A workbook produced by the xlsx skill is the calculation itself: change an assumption and the totals move. That single difference is the whole reason to install it.",
        "It is also the fastest way to restructure a file somebody else built. Reading an existing workbook and rewriting its layout, headers or formulas is tedious by hand and mechanical for an agent."
      ]
    },
    {
      "heading": "Where it disappoints",
      "paragraphs": [
        "Very large workbooks and heavy pivot or chart work remain awkward, and elaborate conditional formatting is easy to describe and slow to verify. Check the parts that matter rather than assuming the whole file is correct.",
        "As with the other document skills, the license is source available rather than open source, so read it before shipping the skill inside a commercial product."
      ]
    }
  ],
  "faq": [
    {
      "question": "Does it write real formulas or just values?",
      "answer": "It can write real formulas, but be explicit about which cells should be formulas and which should be fixed inputs."
    },
    {
      "question": "Can it edit an existing spreadsheet?",
      "answer": "Yes, it reads existing workbooks and edits them, which is usually faster than rebuilding a file from scratch."
    },
    {
      "question": "Should I use it for data that goes into code?",
      "answer": "Usually not. If a program is the consumer, ask for CSV or JSON and skip the spreadsheet layer entirely."
    }
  ],
  "sources": [
    {
      "label": "anthropics/skills on GitHub",
      "url": "https://github.com/anthropics/skills",
      "kind": "repository"
    },
    {
      "label": "anthropics/skills, xlsx skill directory",
      "url": "https://github.com/anthropics/skills/tree/main/skills/xlsx",
      "kind": "documentation"
    }
  ],
  "machineReadable": {
    "markdown": "https://bestskillsforclaude.com/en/skills/xlsx/content.md",
    "json": "https://bestskillsforclaude.com/en/skills/xlsx/skill.json"
  },
  "disclosure": "Editorial desk review based on the publisher's own repository. Not a security audit, a benchmark or a guarantee of maintenance."
}