DOCX

DOCX creation, editing, and analysis

Overview

A .docx file is a ZIP archive containing XML files.

Quick Reference

Converting .doc to .docx

Legacy .doc files must be converted before editing:

soffice --headless --convert-to docx document.doc

Reading Content

# Text extraction with tracked changes
pandoc --track-changes=all document.docx -o output.md

# Raw XML access
python scripts/unpack.py document.docx unpacked/

Converting to Images

soffice --headless --convert-to pdf document.docx
pdftoppm -jpeg -r 150 document.pdf page

Accepting Tracked Changes

To produce a clean document with all tracked changes accepted (requires LibreOffice):

python scripts/accept_changes.py input.docx output.docx

Creating New Documents

Generate .docx files with JavaScript. Install as a project dependency: npm install docx

⚠️ CRITICAL: In docx-js, use JavaScript escapes (\") for quotes. NEVER use XML entities (“) - they will appear as literal garbage text.

After generating a new docx, always run:

python scripts/sanitize.py input.docx

Setup

const { Document, Packer, Paragraph, TextRun, Table, TableRow, TableCell, ImageRun,
        Header, Footer, AlignmentType, PageOrientation, LevelFormat, ExternalHyperlink,
        HeadingLevel, BorderStyle, WidthType, ShadingType,
        VerticalAlign, PageNumber, PageBreak } = require('docx');

// CRITICAL: Use exactly ONE section - multiple sections create blank pages
const doc = new Document({ sections: [{ children: [/* ALL content here */] }] });
Packer.toBuffer(doc).then(buffer => fs.writeFileSync("doc.docx", buffer));

Page Size

// CRITICAL: docx-js defaults to A4, not US Letter
// Always set page size explicitly for consistent results
sections: [{
  properties: {
    page: {
      size: {
        width: 12240,   // 8.5 inches in DXA
        height: 15840   // 11 inches in DXA
      },
      margin: { top: 1440, right: 1440, bottom: 1440, left: 1440 } // 1 inch margins
    }
  },
  children: [/* ALL content goes here in this single section */]
}]

Common page sizes (DXA units, 1440 DXA = 1 inch):

Fonts and CJK Support

CRITICAL: For documents containing Chinese/Japanese/Korean text, you MUST configure fonts for both ASCII and East Asian characters. Using only ASCII fonts (like Arial) will cause CJK characters to display incorrectly or as boxes.

Font Configuration by Character Type

Word documents use different font slots for different character types:

• ascii / hAnsi: Latin characters (A-Z, a-z, numbers)
• eastAsia: CJK characters (Chinese, Japanese, Korean)
• cs: Complex scripts (Arabic, Hebrew, etc.)

Recommended Font Combinations

Best practice: Use Microsoft YaHei for CJK as it's available on most platforms and renders well.

Basic Font Setup (ASCII only - English documents)

const doc = new Document({
  styles: {
    default: { document: { run: { font: "Arial", size: 24 } } }
  }
});

CJK Font Setup (Documents with Chinese/Japanese/Korean)

const doc = new Document({
  styles: {
    default: {
      document: {
        run: {
          font: {
            ascii: "Arial",
            hAnsi: "Arial",
            eastAsia: "Microsoft YaHei"
          },
          size: 24
        }
      }
    },
    paragraphStyles: [
      { id: "Heading1", name: "Heading 1", basedOn: "Normal", next: "Normal", quickFormat: true,
        run: {
          size: 32, bold: true,
          font: { ascii: "Arial", hAnsi: "Arial", eastAsia: "Microsoft YaHei" }
        },
        paragraph: { spacing: { before: 240, after: 240 }, outlineLevel: 0, keepNext: false, keepLines: false } },
      { id: "Heading2", name: "Heading 2", basedOn: "Normal", next: "Normal", quickFormat: true,
        run: {
          size: 28, bold: true,
          font: { ascii: "Arial", hAnsi: "Arial", eastAsia: "Microsoft YaHei" }
        },
        paragraph: { spacing: { before: 180, after: 180 }, outlineLevel: 1, keepNext: false, keepLines: false } },
    ]
  },
  sections: [{
    children: [
      new Paragraph({ heading: HeadingLevel.HEADING_1, children: [new TextRun("标题 Title")] }),
    ]
  }]
});

Platform-Adaptive Font Selection

For maximum compatibility across different operating systems:

const os = require('os');

function getCJKFont() {
  const platform = os.platform();
  if (platform === 'darwin') {
    return 'PingFang SC';  // macOS
  } else if (platform === 'win32') {
    return 'Microsoft YaHei';  // Windows
  } else {
    return 'Noto Sans CJK SC';  // Linux
  }
}

const cjkFont = getCJKFont();
const doc = new Document({
  styles: {
    default: {
      document: {
        run: {
          font: { ascii: "Arial", hAnsi: "Arial", eastAsia: cjkFont },
          size: 24
        }
      }
    }
  }
});

Styles (Override Built-in Headings)

Keep titles black for readability. Set keepNext: false and keepLines: false to allow natural page flow.

const doc = new Document({
  styles: {
    default: {
      document: {
        run: {
          font: { ascii: "Arial", hAnsi: "Arial", eastAsia: "Microsoft YaHei" },
          size: 24
        }
      }
    },
    paragraphStyles: [
      // IMPORTANT: Use exact IDs to override built-in styles
      // IMPORTANT: Set keepNext/keepLines to false to allow natural page flow
      { id: "Heading1", name: "Heading 1", basedOn: "Normal", next: "Normal", quickFormat: true,
        run: { size: 32, bold: true, font: { ascii: "Arial", hAnsi: "Arial", eastAsia: "Microsoft YaHei" } },
        paragraph: { spacing: { before: 240, after: 240 }, outlineLevel: 0, keepNext: false, keepLines: false } },
      { id: "Heading2", name: "Heading 2", basedOn: "Normal", next: "Normal", quickFormat: true,
        run: { size: 28, bold: true, font: { ascii: "Arial", hAnsi: "Arial", eastAsia: "Microsoft YaHei" } },
        paragraph: { spacing: { before: 180, after: 180 }, outlineLevel: 1, keepNext: false, keepLines: false } },
    ]
  },
  sections: [{
    children: [
      new Paragraph({ heading: HeadingLevel.HEADING_1, children: [new TextRun("标题 Title")] }),
    ]
  }]
});

Special Characters in docx-js

⚠️ CRITICAL: Use JavaScript escapes, NOT XML entities.

// ✅ CORRECT - use JavaScript backslash escapes
new TextRun("这是中文内容")
new TextRun("He said \"Hello\" and replied \"你好\"")
new TextRun("包含\"双引号\"的内容")

// ❌ WRONG - XML entities will display as garbage text in the document
new TextRun("“Hello”")  // Shows literal: “Hello”
new TextRun("Tom’s book")  // Shows literal: Tom’s book

// ❌ WRONG - do NOT convert characters to \uXXXX escapes
new TextRun("\u8fd9\u662f\u4e2d\u6587")  // Makes code unreadable

Remember:

• docx-js handles XML internally - you write JavaScript strings, not XML
• XML entities are ONLY for the "Editing Existing Documents" workflow (raw XML editing)
• When in doubt, use \" for quotes

Lists (NEVER use unicode bullets)

// ❌ WRONG - never manually insert bullet characters
new Paragraph({ children: [new TextRun("• Item")] })  // BAD
new Paragraph({ children: [new TextRun("\u2022 Item")] })  // BAD

// ✅ CORRECT - use numbering config with LevelFormat.BULLET
const doc = new Document({
  numbering: {
    config: [
      { reference: "bullets",
        levels: [{ level: 0, format: LevelFormat.BULLET, text: "•", alignment: AlignmentType.LEFT,
          style: { paragraph: { indent: { left: 720, hanging: 360 } } } }] },
      { reference: "numbers",
        levels: [{ level: 0, format: LevelFormat.DECIMAL, text: "%1.", alignment: AlignmentType.LEFT,
          style: { paragraph: { indent: { left: 720, hanging: 360 } } } }] },
    ]
  },
  sections: [{
    children: [
      new Paragraph({ numbering: { reference: "bullets", level: 0 },
        children: [new TextRun("Bullet item")] }),
      new Paragraph({ numbering: { reference: "numbers", level: 0 },
        children: [new TextRun("Numbered item")] }),
    ]
  }]
});

// ⚠️ Each reference creates INDEPENDENT numbering
// Same reference = continues (1,2,3 then 4,5,6)
// Different reference = restarts (1,2,3 then 1,2,3)

Tables

CRITICAL: Tables need dual widths - set both columnWidths on the table AND width on each cell. Without both, tables render incorrectly on some platforms.

CRITICAL: Tables should not split across pages - use cantSplit: true on TableRow to keep each row intact.

// CRITICAL: Always set table width for consistent rendering
// CRITICAL: Use ShadingType.CLEAR (not SOLID) to prevent black backgrounds
// CRITICAL: Use cantSplit: true to prevent rows from breaking across pages
const border = { style: BorderStyle.SINGLE, size: 1, color: "CCCCCC" };
const borders = { top: border, bottom: border, left: border, right: border };

new Table({
  width: { size: 100, type: WidthType.PERCENTAGE }, // Always set table width
  columnWidths: [4680, 4680], // Set at table level (DXA: 1440 = 1 inch)
  rows: [
    new TableRow({
      cantSplit: true, // Prevent row from splitting across pages
      children: [
        new TableCell({
          borders,
          width: { size: 4680, type: WidthType.DXA }, // Also set on each cell
          shading: { fill: "D5E8F0", type: ShadingType.CLEAR }, // CLEAR not SOLID
          margins: { top: 80, bottom: 80, left: 120, right: 120 }, // Cell padding (internal, not added to width)
          children: [new Paragraph({ children: [new TextRun("Cell")] })]
        })
      ]
    })
  ]
})

Table width calculation:

Use WidthType.PERCENTAGE for simplicity, or WidthType.DXA for precise control:

// Option 1: Percentage (recommended - automatically fits content area)
width: { size: 100, type: WidthType.PERCENTAGE }

// Option 2: DXA (precise control)
// Table width = sum of columnWidths = content width
// US Letter with 1" margins: 12240 - 2880 = 9360 DXA
width: { size: 9360, type: WidthType.DXA },
columnWidths: [7000, 2360]  // Must sum to table width

Width rules:

• Table width must equal the sum of columnWidths
• Cell width must match corresponding columnWidth
• Cell margins are internal padding - they reduce content area, not add to cell width
• For full-width tables: use content width (page width minus left and right margins)

Images

// CRITICAL: type parameter is REQUIRED
new Paragraph({
  children: [new ImageRun({
    type: "png", // Required: png, jpg, jpeg, gif, bmp, svg
    data: fs.readFileSync("image.png"),
    transformation: { width: 200, height: 150 },
    altText: { title: "Title", description: "Desc", name: "Name" } // All three required
  })]
})

Page Breaks and Pagination

Pagination strategy:

• Cover page: Use explicit PageBreak after cover content
• Images/Tables: Keep intact, do not split across pages
• Headings/Paragraphs: Allow natural flow, no forced page breaks

// CRITICAL: PageBreak must be inside a Paragraph
new Paragraph({ children: [new PageBreak()] })

// Or use pageBreakBefore (use sparingly - only for cover pages or major sections)
new Paragraph({ pageBreakBefore: true, children: [new TextRun("New page")] })

IMPORTANT: Avoid excessive whitespace - Word's default heading styles set keepNext: true which forces headings to stay with the following paragraph. This causes pages with only a heading at the bottom and large blank areas. Always set keepNext: false and keepLines: false on heading styles (see Styles section above).

**⚠️ CRITICAL: Each section generates at least one page. If you create an empty section (e.g., with page properties only and children: []) followed by a content section, the empty section will render as a blank first page. Use PageBreak within a single section instead.

Headers/Footers

sections: [{
  properties: {
    page: { margin: { top: 1440, right: 1440, bottom: 1440, left: 1440 } } // 1440 = 1 inch
  },
  headers: {
    default: new Header({ children: [new Paragraph({ children: [new TextRun("Header")] })] })
  },
  footers: {
    default: new Footer({ children: [new Paragraph({
      children: [new TextRun("Page "), new TextRun({ children: [PageNumber.CURRENT] })]
    })] })
  },
  children: [/* content */]
}]

Critical Rules for docx-js

• Use exactly ONE section - put ALL content in a single section's children array. Multiple sections cause blank pages (each empty section renders as a blank page). Never create an empty section followed by a content section
• Set page size explicitly - docx-js defaults to A4; use US Letter (12240 x 15840 DXA) for US documents
• Configure CJK fonts for Chinese/Japanese/Korean - use font: { ascii: "Arial", hAnsi: "Arial", eastAsia: "Microsoft YaHei" } to prevent garbled text
• Use JavaScript escapes for quotes - use \" not XML entities; “ will show as garbage text
• Never use \n - use separate Paragraph elements
• Never use unicode bullets - use LevelFormat.BULLET with numbering config
• PageBreak must be in Paragraph - standalone creates invalid XML
• ImageRun requires type - always specify png/jpg/etc
• Always set table width - use { size: 100, type: WidthType.PERCENTAGE } for full width
• Tables need dual widths - columnWidths array AND cell width, both must match
• Table width = sum of columnWidths - for DXA, ensure they add up exactly
• Always add cell margins - use margins: { top: 80, bottom: 80, left: 120, right: 120 } for readable padding
• Use ShadingType.CLEAR - never SOLID for table shading
• Override built-in styles - use exact IDs: "Heading1", "Heading2", etc.
• Include outlineLevel - required in heading styles (0 for H1, 1 for H2, etc.)
• Set keepNext: false on headings - prevents excessive whitespace from headings being pushed to next page
• Set cantSplit: true on table rows - keeps tables intact across page boundaries
• No table of contents - do not generate any TOC or directory page; start directly with document content
• Always run sanitize.py after creation - it checks for and removes text-only TOC blocks and redundant blank pages

Editing Existing Documents

⚠️ This section is for editing RAW XML files (unpack/pack workflow). XML entities (“) are ONLY valid here, NOT in docx-js code above.

Follow all 3 steps in order.

Step 1: Unpack

python scripts/unpack.py document.docx unpacked/

Extracts XML, pretty-prints, merges adjacent runs, and converts smart quotes to XML entities (“ etc.) so they survive editing. Use --merge-runs false to skip run merging.

Step 2: Edit XML

Edit files in unpacked/word/. See XML Reference below for patterns.

Use "AI Assistant" as the author for tracked changes and comments, unless the user explicitly requests use of a different name.

Use the Edit tool directly for string replacement. Do not write Python scripts. Scripts introduce unnecessary complexity. The Edit tool shows exactly what is being replaced.

CRITICAL: Use smart quotes for new content. When adding text with apostrophes or quotes, use XML entities to produce smart quotes:

<!-- Use these entities for professional typography -->
<w:t>Here&#x2019;s a quote: &#x201C;Hello&#x201D;</w:t>

Adding comments: Use comment.py to handle boilerplate across multiple XML files (text must be pre-escaped XML):

python scripts/comment.py unpacked/ 0 "Comment text with & and ’"
python scripts/comment.py unpacked/ 1 "Reply text" --parent 0  # reply to comment 0
python scripts/comment.py unpacked/ 0 "Text" --author "Custom Author"  # custom author name

Then add markers to document.xml (see Comments in XML Reference).

Step 3: Pack

python scripts/pack.py unpacked/ output.docx --original document.docx

Validates with auto-repair, condenses XML, and creates DOCX. Use --validate false to skip.

Auto-repair will fix:

• durableId >= 0x7FFFFFFF (regenerates valid ID)
• Missing xml:space="preserve" on <w:t> with whitespace

Auto-repair won't fix:

• Malformed XML, invalid element nesting, missing relationships, schema violations

Common Pitfalls

• Replace entire <w:r> elements: When adding tracked changes, replace the whole <w:r>...</w:r> block with <w:del>...<w:ins>... as siblings. Don't inject tracked change tags inside a run.
• Preserve <w:rPr> formatting: Copy the original run's <w:rPr> block into your tracked change runs to maintain bold, font size, etc.

XML Reference

Schema Compliance

• Element order in <w:pPr>: <w:pStyle>, <w:numPr>, <w:spacing>, <w:ind>, <w:jc>, <w:rPr> last
• Whitespace: Add xml:space="preserve" to <w:t> with leading/trailing spaces
• RSIDs: Must be 8-digit hex (e.g., 00AB1234)

Tracked Changes

Insertion:

<w:ins w:id="1" w:author="AI Assistant" w:date="2025-01-01T00:00:00Z">
  <w:r><w:t>inserted text</w:t></w:r>
</w:ins>

Deletion:

<w:del w:id="2" w:author="AI Assistant" w:date="2025-01-01T00:00:00Z">
  <w:r><w:delText>deleted text</w:delText></w:r>
</w:del>

Inside <w:del>: Use <w:delText> instead of <w:t>, and <w:delInstrText> instead of <w:instrText>.

Minimal edits - only mark what changes:

<!-- Change "30 days" to "60 days" -->
<w:r><w:t>The term is </w:t></w:r>
<w:del w:id="1" w:author="AI Assistant" w:date="...">
  <w:r><w:delText>30</w:delText></w:r>
</w:del>
<w:ins w:id="2" w:author="AI Assistant" w:date="...">
  <w:r><w:t>60</w:t></w:r>
</w:ins>
<w:r><w:t> days.</w:t></w:r>

Deleting entire paragraphs/list items - when removing ALL content from a paragraph, also mark the paragraph mark as deleted so it merges with the next paragraph. Add <w:del/> inside <w:pPr><w:rPr>:

<w:p>
  <w:pPr>
    <w:numPr>...</w:numPr>  <!-- list numbering if present -->
    <w:rPr>
      <w:del w:id="1" w:author="AI Assistant" w:date="2025-01-01T00:00:00Z"/>
    </w:rPr>
  </w:pPr>
  <w:del w:id="2" w:author="AI Assistant" w:date="2025-01-01T00:00:00Z">
    <w:r><w:delText>Entire paragraph content being deleted...</w:delText></w:r>
  </w:del>
</w:p>

Without the <w:del/> in <w:pPr><w:rPr>, accepting changes leaves an empty paragraph/list item.

Rejecting another author's insertion - nest deletion inside their insertion:

<w:ins w:author="Jane" w:id="5">
  <w:del w:author="AI Assistant" w:id="10">
    <w:r><w:delText>their inserted text</w:delText></w:r>
  </w:del>
</w:ins>

Restoring another author's deletion - add insertion after (don't modify their deletion):

<w:del w:author="Jane" w:id="5">
  <w:r><w:delText>deleted text</w:delText></w:r>
</w:del>
<w:ins w:author="AI Assistant" w:id="10">
  <w:r><w:t>deleted text</w:t></w:r>
</w:ins>

Comments

After running comment.py (see Step 2), add markers to document.xml. For replies, use --parent flag and nest markers inside the parent's.

CRITICAL: <w:commentRangeStart> and <w:commentRangeEnd> are siblings of <w:r>, never inside <w:r>.

<!-- Comment markers are direct children of w:p, never inside w:r -->
<w:commentRangeStart w:id="0"/>
<w:del w:id="1" w:author="AI Assistant" w:date="2025-01-01T00:00:00Z">
  <w:r><w:delText>deleted</w:delText></w:r>
</w:del>
<w:r><w:t> more text</w:t></w:r>
<w:commentRangeEnd w:id="0"/>
<w:r><w:rPr><w:rStyle w:val="CommentReference"/></w:rPr><w:commentReference w:id="0"/></w:r>

<!-- Comment 0 with reply 1 nested inside -->
<w:commentRangeStart w:id="0"/>
  <w:commentRangeStart w:id="1"/>
  <w:r><w:t>text</w:t></w:r>
  <w:commentRangeEnd w:id="1"/>
<w:commentRangeEnd w:id="0"/>
<w:r><w:rPr><w:rStyle w:val="CommentReference"/></w:rPr><w:commentReference w:id="0"/></w:r>
<w:r><w:rPr><w:rStyle w:val="CommentReference"/></w:rPr><w:commentReference w:id="1"/></w:r>

Images

1. Add image file to word/media/
2. Add relationship to word/_rels/document.xml.rels:

<Relationship Id="rId5" Type=".../image" Target="media/image1.png"/>

3. Add content type to [Content_Types].xml:

<Default Extension="png" ContentType="image/png"/>

4. Reference in document.xml:

<w:drawing>
  <wp:inline>
    <wp:extent cx="914400" cy="914400"/>  <!-- EMUs: 914400 = 1 inch -->
    <a:graphic>
      <a:graphicData uri=".../picture">
        <pic:pic>
          <pic:blipFill><a:blip r:embed="rId5"/></pic:blipFill>
        </pic:pic>
      </a:graphicData>
    </a:graphic>
  </wp:inline>
</w:drawing>

Dependencies

• pandoc: Text extraction
• docx: npm install docx (project dependency for new documents)
• LibreOffice: PDF conversion
• Poppler: pdftoppm for images