Pretty Tables

Knowledge
TablesDocxWordDocument

Create beautiful, full-width tables in Word documents using the docx npm library. Tables are properly sized, centered, and styled. Use when you need to create DOCX files with professional-looking tables like itineraries, schedules, data tables, or reports.

Install

openclaw skills install @happytreees/pretty-tables

pretty-tables

Create beautiful tables in Word documents that work consistently across Word and Google Docs.

⚠️ THE 5 CRITICAL RULES

After extensive testing, these are the essential patterns for tables that render correctly everywhere:

1. Dual-Width Sizing (MOST CRITICAL)

Every table needs widths set in TWO places — on the table itself AND on each individual cell:

// Table level
new Table({
  width: { size: 9360, type: WidthType.DXA },  // Total width
  columnWidths: [1872, 7488],                   // Per-column widths
  rows: [...]
})

// Cell level - EVERY cell needs this!
new TableCell({
  width: { size: 1872, type: WidthType.DXA },   // This cell's width
  children: [...]
})

If either is missing, the table renders incorrectly on some platforms.

2. Use DXA Only, Never Percentages

Percentages break in Google Docs. Always use DXA (twips):

  • 1 inch = 1440 DXA
  • US Letter (8.5") with 1" margins = 9360 DXA content width
// ❌ WRONG - breaks in Google Docs
width: { size: 100, type: WidthType.PERCENTAGE }

// ✅ CORRECT
width: { size: 9360, type: WidthType.DXA }

3. Use ShadingType.CLEAR, Not SOLID

This is a subtle but critical gotcha:

const { ShadingType } = require('docx');

// ❌ WRONG - produces BLACK background
shading: { type: ShadingType.SOLID, fill: "E0F2F1" }

// ✅ CORRECT - applies the fill color
shading: { type: ShadingType.CLEAR, fill: "E0F2F1" }

4. Add Cell Padding (Margins)

Keep text from crowding the borders:

const cellMargins = { top: 80, bottom: 80, left: 120, right: 120 };

new TableCell({
  children: [...],
  margins: cellMargins
})

5. Column Widths Must Sum Exactly

For US Letter with 1" margins: 9360 DXA

// 2 columns: 20% + 80%
columnWidths: [1872, 7488]  // = 9360 ✓

// 3 columns: equal
columnWidths: [3120, 3120, 3120]  // = 9360 ✓

// 3 columns: 25% + 25% + 50%
columnWidths: [2340, 2340, 4680]  // = 9360 ✓

Complete Working Example

const { Document, Packer, Paragraph, TextRun, Table, TableRow, TableCell, 
         WidthType, AlignmentType, BorderStyle, TableLayoutType, ShadingType } = require('docx');
const fs = require('fs');

// Constants
const TOTAL_WIDTH = 9360;  // US Letter with 1" margins
const TIME_COL = 1872;     // 20%
const CONTENT_COL = 7488;  // 80%

// Light gray borders
const cellBorders = {
  top: { style: BorderStyle.SINGLE, size: 1, color: "CCCCCC" },
  bottom: { style: BorderStyle.SINGLE, size: 1, color: "CCCCCC" },
  left: { style: BorderStyle.SINGLE, size: 1, color: "CCCCCC" },
  right: { style: BorderStyle.SINGLE, size: 1, color: "CCCCCC" }
};

// Cell padding
const cellMargins = { top: 80, bottom: 80, left: 120, right: 120 };

// Table helper
function table(columnWidths, rows) {
  return new Table({
    layout: TableLayoutType.FIXED,
    width: { size: columnWidths.reduce((a, b) => a + b, 0), type: WidthType.DXA },
    columnWidths: columnWidths,
    rows: rows
  });
}

// Header row
function headerRow(text, color) {
  return new TableRow({
    children: [
      new TableCell({
        children: [new Paragraph({ 
          children: [new TextRun({ text, bold: true, size: 32, color: "FFFFFF" })],
          alignment: AlignmentType.CENTER
        })],
        width: { size: TIME_COL + CONTENT_COL, type: WidthType.DXA },
        columnSpan: 2,
        shading: { type: ShadingType.CLEAR, fill: color },
        borders: cellBorders,
        margins: cellMargins
      })
    ]
  });
}

// Data row
function dataRow(time, activity, color) {
  return new TableRow({
    children: [
      new TableCell({
        children: [new Paragraph({ 
          children: [new TextRun({ text: time, bold: true, size: 26, color })],
          alignment: AlignmentType.CENTER
        })],
        width: { size: TIME_COL, type: WidthType.DXA },
        borders: cellBorders,
        margins: cellMargins
      }),
      new TableCell({
        children: [new Paragraph({ 
          children: [new TextRun({ text: activity, size: 26 })]
        })],
        width: { size: CONTENT_COL, type: WidthType.DXA },
        borders: cellBorders,
        margins: cellMargins
      })
    ]
  });
}

// Build document
const doc = new Document({
  sections: [{
    properties: { 
      page: { margin: { top: 1440, right: 1440, bottom: 1440, left: 1440 } }
    },
    children: [
      table([TIME_COL, CONTENT_COL], [
        headerRow("SCHEDULE", "1565C0"),
        dataRow("9:00 AM", "Arrive at destination", "1565C0"),
        dataRow("10:00 AM", "Morning activity", "1565C0"),
        dataRow("12:00 PM", "Lunch break", "1565C0"),
      ])
    ]
  }]
});

Packer.toBuffer(doc).then(buffer => {
  fs.writeFileSync('output.docx', buffer);
});

Column Width Cheat Sheet

For US Letter (8.5") with 1" margins = 9360 DXA:

LayoutColumn WidthsSum
2 cols (20/80)[1872, 7488]9360
2 cols (25/75)[2340, 7020]9360
2 cols (30/70)[2808, 6552]9360
2 cols (equal)[4680, 4680]9360
3 cols (equal)[3120, 3120, 3120]9360
3 cols (25/25/50)[2340, 2340, 4680]9360
3 cols (20/30/50)[1872, 2808, 4680]9360
4 cols (equal)[2340, 2340, 2340, 2340]9360

Common Mistakes

Missing cell widths:

new TableCell({ children: [...] })  // No width!

Using percentages:

width: { size: 100, type: WidthType.PERCENTAGE }  // Breaks in Google Docs

Wrong shading type:

shading: { type: ShadingType.SOLID, fill: "E0F2F1" }  // BLACK background!

Columns don't sum:

columnWidths: [2000, 7000]  // = 9000, not 9360

Correct:

new TableCell({
  width: { size: 1872, type: WidthType.DXA },
  shading: { type: ShadingType.CLEAR, fill: "E0F2F1" },
  margins: { top: 80, bottom: 80, left: 120, right: 120 },
  borders: cellBorders,
  children: [...]
})

Color Palette

Header colors:

ColorHexUse
Blue1565C0Default headers
RedC62828Important
Green2E7D32Success
OrangeEF6C00Warning
Purple6A1B9ASpecial
Teal00695CInfo

Light backgrounds:

ColorHexUse
Light BlueBBDEFBHighlight
Light GreenC8E6C9Success
Light YellowFFF9C4Note
Light GrayF5F5F5Alternating

Why This Works

The combination of:

  1. Exact DXA sizing on both table and cells
  2. ShadingType.CLEAR for correct colors
  3. Consistent padding for readability
  4. Precise column sums for layout

...produces tables that render correctly in Microsoft Word, Google Docs, and other DOCX viewers.

Troubleshooting

Q: Table is narrow in Google Docs

  • Make sure you're using WidthType.DXA, not PERCENTAGE
  • Check that every TableCell has a width property

Q: Cell backgrounds are black

  • Change ShadingType.SOLID to ShadingType.CLEAR

Q: Text touches the borders

  • Add margins: { top: 80, bottom: 80, left: 120, right: 120 } to each cell

Q: Columns are uneven

  • Verify column widths sum exactly to table width (9360 for 1" margins)