docx

DOCX Processing Guide

Overview

This guide covers creating, editing, and analyzing Word documents (.docx files). Use this skill when you need to programmatically create new Word documents, make targeted edits to existing files, or extract content.

Creating Documents

Use the docx JavaScript library for programmatic document creation. The library provides a powerful API for building Word documents with full formatting control.

Page Sizing

Always explicitly set page size — docx-js defaults to A4 (11,906 × 16,838 DXA), not US Letter. Specify dimensions using DXA units, where 1 inch = 1440 DXA.

For US Letter (8.5" × 11"):

• Width: 12,240 DXA
• Height: 15,840 DXA
• With standard 1" margins: content area is 10,240 × 13,840 DXA

For landscape orientation, pass portrait dimensions with landscape: true — the library handles internal conversion:

const doc = new Document({
  sections: [{
    properties: {
      pageHeight: 15840,  // Portrait height
      pageWidth: 12240,   // Portrait width
      landscape: true,    // Library rotates internally
    }
  }]
});

Tables

Tables require dual width specifications. Always specify both columnWidths array AND individual cell width properties, with all values using WidthType.DXA (percentage widths break in Google Docs).

Table width must equal the sum of column widths:

const columnWidths = [3000, 4000, 3000];  // Total: 10000
const table = new Table({
  columnWidths: columnWidths,
  width: { size: 10000, type: WidthType.DXA },  // Match total
  rows: [
    new TableRow({
      cells: [
        new TableCell({
          children: [...],
          width: { size: 3000, type: WidthType.DXA }
        }),
        // ... more cells
      ]
    })
  ]
});

Use ShadingType.CLEAR for cell background colors to avoid rendering issues.

Bullets and Lists

Never insert bullet points using manual Unicode characters. Instead, use the numbering system with LevelFormat.BULLET: