DOCX JS

DOCX Library Tutorial

Generate .docx files with JavaScript/TypeScript.

Important: Read this entire document before starting. Critical formatting rules and common pitfalls are covered throughout - skipping sections may result in corrupted files or rendering issues.

Setup

Assumes docx is already installed globally If not installed: npm install -g docx

const { Document, Packer, Paragraph, TextRun, Table, TableRow, TableCell, ImageRun, Media, 
        Header, Footer, AlignmentType, PageOrientation, LevelFormat, ExternalHyperlink, 
        InternalHyperlink, TableOfContents, HeadingLevel, BorderStyle, WidthType, TabStopType, 
        TabStopPosition, UnderlineType, ShadingType, VerticalAlign, SymbolRun, PageNumber,
        FootnoteReferenceRun, Footnote, PageBreak } = require('docx');

// Create & Save
const doc = new Document({ sections: [{ children: [/* content */] }] });
Packer.toBuffer(doc).then(buffer => fs.writeFileSync("doc.docx", buffer)); // Node.js
Packer.toBlob(doc).then(blob => { /* download logic */ }); // Browser

Text & Formatting

// IMPORTANT: Never use \n for line breaks - always use separate Paragraph elements
// ❌ WRONG: new TextRun("Line 1\nLine 2")
// ✅ CORRECT: new Paragraph({ children: [new TextRun("Line 1")] }), new Paragraph({ children: [new TextRun("Line 2")] })

// Basic text with all formatting options
new Paragraph({
  alignment: AlignmentType.CENTER,
  spacing: { before: 200, after: 200 },
  indent: { left: 720, right: 720 },
  children: [
    new TextRun({ text: "Bold", bold: true }),
    new TextRun({ text: "Italic", italics: true }),
    new TextRun({ text: "Underlined", underline: { type: UnderlineType.DOUBLE, color: "FF0000" } }),
    new TextRun({ text: "Colored", color: "FF0000", size: 28, font: "Arial" }), // Arial default
    new TextRun({ text: "Highlighted", highlight: "yellow" }),
    new TextRun({ text: "Strikethrough", strike: true }),
    new TextRun({ text: "x2", superScript: true }),
    new TextRun({ text: "H2O", subScript: true }),
    new TextRun({ text: "SMALL CAPS", smallCaps: true }),
    new SymbolRun({ char: "2022", font: "Symbol" }), // Bullet •
    new SymbolRun({ char: "00A9", font: "Arial" })   // Copyright © - Arial for symbols
  ]
})

Styles & Professional Formatting

const doc = new Document({
  styles: {
    default: { document: { run: { font: "Arial", size: 24 } } }, // 12pt default
    paragraphStyles: [
      // Document title style - override built-in Title style
      { id: "Title", name: "Title", basedOn: "Normal",
        run: { size: 56, bold: true, color: "000000", font: "Arial" },
        paragraph: { spacing: { before: 240, after: 120 }, alignment: AlignmentType.CENTER } },
      // IMPORTANT: Override built-in heading styles by using their exact IDs
      { id: "Heading1", name: "Heading 1", basedOn: "Normal", next: "Normal", quickFormat: true,
        run: { size: 32, bold: true, color: "000000", font: "Arial" }, // 16pt
        paragraph: { spacing: { before: 240, after: 240 }, outlineLevel: 0 } }, // Required for TOC
      { id: "Heading2", name: "Heading 2", basedOn: "Normal", next: "Normal", quickFormat: true,
        run: { size: 28, bold: true, color: "000000", font: "Arial" }, // 14pt
        paragraph: { spacing: { before: 180, after: 180 }, outlineLevel: 1 } },
      // Custom styles use your own IDs
      { id: "myStyle", name: "My Style", basedOn: "Normal",
        run: { size: 28, bold: true, color: "000000" },
        paragraph: { spacing: { after: 120 }, alignment: AlignmentType.CENTER } }
    ],
    characterStyles: [{ id: "myCharStyle", name: "My Char Style",
      run: { color: "FF0000", bold: true, underline: { type: UnderlineType.SINGLE } } }]
  },
  sections: [{
    properties: { page: { margin: { top: 1440, right: 1440, bottom: 1440, left: 1440 } } },
    children: [
      new Paragraph({ heading: HeadingLevel.TITLE, children: [new TextRun("Document Title")] }), // Uses overridden Title style
      new Paragraph({ heading: HeadingLevel.HEADING_1, children: [new TextRun("Heading 1")] }), // Uses overridden Heading1 style
      new Paragraph({ style: "myStyle", children: [new TextRun("Custom paragraph style")] }),
      new Paragraph({ children: [
        new TextRun("Normal with "),
        new TextRun({ text: "custom char style", style: "myCharStyle" })
      ]})
    ]
  }]
});

Professional Font Combinations:

• Arial (Headers) + Arial (Body) - Most universally supported, clean and professional
• Times New Roman (Headers) + Arial (Body) - Classic serif headers with modern sans-serif body
• Georgia (Headers) + Verdana (Body) - Optimized for screen reading, elegant contrast

Key Styling Principles:

• Override built-in styles: Use exact IDs like "Heading1", "Heading2", "Heading3" to override Word's built-in heading styles
• HeadingLevel constants: HeadingLevel.HEADING_1 uses "Heading1" style, HeadingLevel.HEADING_2 uses "Heading2" style, etc.
• Include outlineLevel: Set outlineLevel: 0 for H1, outlineLevel: 1 for H2, etc. to ensure TOC works correctly
• Use custom styles instead of inline formatting for consistency
• Set a default font using styles.default.document.run.font - Arial is universally supported
• Establish visual hierarchy with different font sizes (titles > headers > body)
• Add proper spacing with before and after paragraph spacing
• Use colors sparingly: Default to black (000000) and shades of gray for titles and headings (heading 1, heading 2, etc.)
• Set consistent margins (1440 = 1 inch is standard)

Lists (ALWAYS USE PROPER LISTS - NEVER USE UNICODE BULLETS)

// Bullets - ALWAYS use the numbering config, NOT unicode symbols
// CRITICAL: Use LevelFormat.BULLET constant, NOT the string "bullet"
const doc = new Document({
  numbering: {
    config: [
      { reference: "bullet-list",
        levels: [{ level: 0, format: LevelFormat.BULLET, text: "•", alignment: AlignmentType.LEFT,
          style: { paragraph: { indent: { left: 720, hanging: 360 } } } }] },
      { reference: "first-numbered-list",
        levels: [{ level: 0, format: LevelFormat.DECIMAL, text: "%1.", alignment: AlignmentType.LEFT,
          style: { paragraph: { indent: { left: 720, hanging: 360 } } } }] },
      { reference: "second-numbered-list", // Different reference = restarts at 1
        levels: [{ level: 0, format: LevelFormat.DECIMAL, text: "%1.", alignment: AlignmentType.LEFT,
          style: { paragraph: { indent: { left: 720, hanging: 360 } } } }] }
    ]
  },
  sections: [{
    children: [
      // Bullet list items
      new Paragraph({ numbering: { reference: "bullet-list", level: 0 },
        children: [new TextRun("First bullet point")] }),
      new Paragraph({ numbering: { reference: "bullet-list", level: 0 },
        children: [new TextRun("Second bullet point")] }),
      // Numbered list items
      new Paragraph({ numbering: { reference: "first-numbered-list", level: 0 },
        children: [new TextRun("First numbered item")] }),
      new Paragraph({ numbering: { reference: "first-numbered-list", level: 0 },
        children: [new TextRun("Second numbered item")] }),
      // ⚠️ CRITICAL: Different reference = INDEPENDENT list that restarts at 1
      // Same reference = CONTINUES previous numbering
      new Paragraph({ numbering: { reference: "second-numbered-list", level: 0 },
        children: [new TextRun("Starts at 1 again (because different reference)")] })
    ]
  }]
});

// ⚠️ CRITICAL NUMBERING RULE: Each reference creates an INDEPENDENT numbered list
// - Same reference = continues numbering (1, 2, 3... then 4, 5, 6...)
// - Different reference = restarts at 1 (1, 2, 3... then 1, 2, 3...)
// Use unique reference names for each separate numbered section!

// ⚠️ CRITICAL: NEVER use unicode bullets - they create fake lists that don't work properly
// new TextRun("• Item")           // WRONG
// new SymbolRun({ char: "2022" }) // WRONG
// ✅ ALWAYS use numbering config with LevelFormat.BULLET for real Word lists

Tables

// Complete table with margins, borders, headers, and bullet points
const tableBorder = { style: BorderStyle.SINGLE, size: 1, color: "CCCCCC" };
const cellBorders = { top: tableBorder, bottom: tableBorder, left: tableBorder, right: tableBorder };

new Table({
  columnWidths: [4680, 4680], // ⚠️ CRITICAL: Set column widths at table level - values in DXA (twentieths of a point)
  margins: { top: 100, bottom: 100, left: 180, right: 180 }, // Set once for all cells
  rows: [
    new TableRow({
      tableHeader: true,
      children: [
        new TableCell({
          borders: cellBorders,
          width: { size: 4680, type: WidthType.DXA }, // ALSO set width on each cell
          // ⚠️ CRITICAL: Always use ShadingType.CLEAR to prevent black backgrounds in Word.
          shading: { fill: "D5E8F0", type: ShadingType.CLEAR }, 
          verticalAlign: VerticalAlign.CENTER,
          children: [new Paragraph({ 
            alignment: AlignmentType.CENTER,
            children: [new TextRun({ text: "Header", bold: true, size: 22 })]
          })]
        }),
        new TableCell({
          borders: cellBorders,
          width: { size: 4680, type: WidthType.DXA }, // ALSO set width on each cell
          shading: { fill: "D5E8F0", type: ShadingType.CLEAR },
          children: [new Paragraph({ 
            alignment: AlignmentType.CENTER,
            children: [new TextRun({ text: "Bullet Points", bold: true, size: 22 })]
          })]
        })
      ]
    }),
    new TableRow({
      children: [
        new TableCell({
          borders: cellBorders,
          width: { size: 4680, type: WidthType.DXA }, // ALSO set width on each cell
          children: [new Paragraph({ children: [new TextRun("Regular data")] })]
        }),
        new TableCell({
          borders: cellBorders,
          width: { size: 4680, type: WidthType.DXA }, // ALSO set width on each cell
          children: [
            new Paragraph({ 
              numbering: { reference: "bullet-list", level: 0 },
              children: [new TextRun("First bullet point")] 
            }),
            new Paragraph({ 
              numbering: { reference: "bullet-list", level: 0 },
              children: [new TextRun("Second bullet point")] 
            })
          ]
        })
      ]
    })
  ]
})

IMPORTANT: Table Width & Borders

• Use BOTH columnWidths: [width1, width2, ...] array AND width: { size: X, type: WidthType.DXA } on each cell
• Values in DXA (twentieths of a point): 1440 = 1 inch, Letter usable width = 9360 DXA (with 1" margins)
• Apply borders to individual TableCell elements, NOT the Table itself

Precomputed Column Widths (Letter size with 1" margins = 9360 DXA total):

• 2 columns: columnWidths: [4680, 4680] (equal width)
• 3 columns: columnWidths: [3120, 3120, 3120] (equal width)

Links & Navigation

// TOC (requires headings) - CRITICAL: Use HeadingLevel only, NOT custom styles
// ❌ WRONG: new Paragraph({ heading: HeadingLevel.HEADING_1, style: "customHeader", children: [new TextRun("Title")] })
// ✅ CORRECT: new Paragraph({ heading: HeadingLevel.HEADING_1, children: [new TextRun("Title")] })
new TableOfContents("Table of Contents", { hyperlink: true, headingStyleRange: "1-3" }),

// External link
new Paragraph({
  children: [new ExternalHyperlink({
    children: [new TextRun({ text: "Google", style: "Hyperlink" })],
    link: "https://www.google.com"
  })]
}),

// Internal link & bookmark
new Paragraph({
  children: [new InternalHyperlink({
    children: [new TextRun({ text: "Go to Section", style: "Hyperlink" })],
    anchor: "section1"
  })]
}),
new Paragraph({
  children: [new TextRun("Section Content")],
  bookmark: { id: "section1", name: "section1" }
}),

Images & Media

// Basic image with sizing & positioning
// CRITICAL: Always specify 'type' parameter - it's REQUIRED for ImageRun
new Paragraph({
  alignment: AlignmentType.CENTER,
  children: [new ImageRun({
    type: "png", // NEW REQUIREMENT: Must specify image type (png, jpg, jpeg, gif, bmp, svg)
    data: fs.readFileSync("image.png"),
    transformation: { width: 200, height: 150, rotation: 0 }, // rotation in degrees
    altText: { title: "Logo", description: "Company logo", name: "Name" } // IMPORTANT: All three fields are required
  })]
})

Page Breaks

// Manual page break
new Paragraph({ children: [new PageBreak()] }),

// Page break before paragraph
new Paragraph({
  pageBreakBefore: true,
  children: [new TextRun("This starts on a new page")]
})

// ⚠️ CRITICAL: NEVER use PageBreak standalone - it will create invalid XML that Word cannot open
// ❌ WRONG: new PageBreak() 
// ✅ CORRECT: new Paragraph({ children: [new PageBreak()] })

Headers/Footers & Page Setup

const doc = new Document({
  sections: [{
    properties: {
      page: {
        margin: { top: 1440, right: 1440, bottom: 1440, left: 1440 }, // 1440 = 1 inch
        size: { orientation: PageOrientation.LANDSCAPE },
        pageNumbers: { start: 1, formatType: "decimal" } // "upperRoman", "lowerRoman", "upperLetter", "lowerLetter"
      }
    },
    headers: {
      default: new Header({ children: [new Paragraph({ 
        alignment: AlignmentType.RIGHT,
        children: [new TextRun("Header Text")]
      })] })
    },
    footers: {
      default: new Footer({ children: [new Paragraph({ 
        alignment: AlignmentType.CENTER,
        children: [new TextRun("Page "), new TextRun({ children: [PageNumber.CURRENT] }), new TextRun(" of "), new TextRun({ children: [PageNumber.TOTAL_PAGES] })]
      })] })
    },
    children: [/* content */]
  }]
});

Tabs

new Paragraph({
  tabStops: [
    { type: TabStopType.LEFT, position: TabStopPosition.MAX / 4 },
    { type: TabStopType.CENTER, position: TabStopPosition.MAX / 2 },
    { type: TabStopType.RIGHT, position: TabStopPosition.MAX * 3 / 4 }
  ],
  children: [new TextRun("Left\tCenter\tRight")]
})

Constants & Quick Reference

• Underlines: SINGLE, DOUBLE, WAVY, DASH
• Borders: SINGLE, DOUBLE, DASHED, DOTTED
• Numbering: DECIMAL (1,2,3), UPPER_ROMAN (I,II,III), LOWER_LETTER (a,b,c)
• Tabs: LEFT, CENTER, RIGHT, DECIMAL
• Symbols: "2022" (•), "00A9" (©), "00AE" (®), "2122" (™), "00B0" (°), "F070" (✓), "F0FC" (✗)

Critical Issues & Common Mistakes

• CRITICAL: PageBreak must ALWAYS be inside a Paragraph - standalone PageBreak creates invalid XML that Word cannot open
• ALWAYS use ShadingType.CLEAR for table cell shading - Never use ShadingType.SOLID (causes black background).
• Measurements in DXA (1440 = 1 inch) | Each table cell needs ≥1 Paragraph | TOC requires HeadingLevel styles only
• ALWAYS use custom styles with Arial font for professional appearance and proper visual hierarchy
• ALWAYS set a default font using styles.default.document.run.font - Arial recommended
• ALWAYS use columnWidths array for tables + individual cell widths for compatibility
• NEVER use unicode symbols for bullets - always use proper numbering configuration with LevelFormat.BULLET constant (NOT the string "bullet")
• NEVER use \n for line breaks anywhere - always use separate Paragraph elements for each line
• ALWAYS use TextRun objects within Paragraph children - never use text property directly on Paragraph
• CRITICAL for images: ImageRun REQUIRES type parameter - always specify "png", "jpg", "jpeg", "gif", "bmp", or "svg"
• CRITICAL for bullets: Must use LevelFormat.BULLET constant, not string "bullet", and include text: "•" for the bullet character
• CRITICAL for numbering: Each numbering reference creates an INDEPENDENT list. Same reference = continues numbering (1,2,3 then 4,5,6). Different reference = restarts at 1 (1,2,3 then 1,2,3). Use unique reference names for each separate numbered section!
• CRITICAL for TOC: When using TableOfContents, headings must use HeadingLevel ONLY - do NOT add custom styles to heading paragraphs or TOC will break
• Tables: Set columnWidths array + individual cell widths, apply borders to cells not table
• Set table margins at TABLE level for consistent cell padding (avoids repetition per cell)