Examples

Quick Start

import { initWasm, Workbook } from 'modern-xlsx';
await initWasm();
const wb = new Workbook();
const ws = wb.addSheet('Hello');
ws.cell('A1').value = 'Hello, World!';
ws.cell('A2').value = 42;
await wb.toFile('hello.xlsx');

Reading and Modifying

import { readFile } from 'modern-xlsx';
const wb = await readFile('input.xlsx');
const ws = wb.getSheet('Sheet1');
if (ws) {
 console.log(ws.cell('A1').value);
 ws.cell('A1').value = 'Updated!';
 await wb.toFile('output.xlsx');
}

Styling Cells

const headerStyle = wb.createStyle()
 .font({ name: 'Arial', size: 14, bold: true, color: 'FFFFFF' })
 .fill({ patternType: 'solid', fgColor: '4472C4' })
 .alignment({ horizontal: 'center', vertical: 'center' })
 .border({ bottom: { style: 'medium', color: '000000' } })
 .build(wb.styles);
const headers = ['Name', 'Age', 'City'];
headers.forEach((h, i) => {
 const cell = ws.cell(`${String.fromCharCode(65 + i)}1`);
 cell.value = h;
 cell.styleIndex = headerStyle;
});

Formulas

ws.cell('A1').value = 100;
ws.cell('A2').value = 200;
ws.cell('A3').value = 300;
ws.cell('A4').formula = 'SUM(A1:A3)';
ws.cell('B1').formula = 'AVERAGE(A1:A3)';

Merged Cells

ws.cell('A1').value = 'Spans three columns';
ws.addMergeCell('A1:C1');

Column Widths and Row Heights

ws.setColumnWidth(1, 30); // Column A
ws.setRowHeight(1, 40); // Row 1
ws.setRowHidden(5, true); // Hide row 5

Frozen Panes

// Freeze top row
ws.frozenPane = { row: 1, column: 0, topLeftCell: 'A2' };
// Freeze first column
ws.frozenPane = { row: 0, column: 1, topLeftCell: 'B1' };
// Freeze both
ws.frozenPane = { row: 1, column: 1, topLeftCell: 'B2' };

Data Validation

// Dropdown list
ws.addValidation('B2', {
 validationType: 'list',
 formula1: '"Yes,No,Maybe"',
 showDropDown: true,
 prompt: 'Select an option',
 promptTitle: 'Choice',
});
// Number range
ws.addValidation('C2', {
 validationType: 'whole',
 operator: 'between',
 formula1: '1',
 formula2: '100',
 errorTitle: 'Invalid',
 error: 'Enter a number between 1 and 100',
});

Hyperlinks

ws.cell('A1').value = 'Visit Example';
ws.addHyperlink('A1', 'https://example.com', {
 display: 'Visit Example',
 tooltip: 'Opens example.com',
});

Comments

ws.cell('A1').value = 'Hover for comment';
ws.addComment('A1', 'Author Name', 'This is a comment on A1');

Named Ranges

wb.addNamedRange('SalesTotal', 'Data!$A1ドル:$A2ドル');
const range = wb.getNamedRange('SalesTotal');

Document Properties

wb.docProperties = {
 title: 'Sales Report Q4',
 creator: 'Finance Team',
 description: 'Quarterly sales data',
 created: '2026-01-01T00:00:00Z',
};

Rich Text

import { RichTextBuilder } from 'modern-xlsx';
const richText = new RichTextBuilder()
 .bold('Important: ')
 .text('Normal text. ')
 .colored('Red text', 'FF0000')
 .styled('Custom', { bold: true, italic: true, fontSize: 14 })
 .build();

Sheet Conversions

import { aoaToSheet, jsonToSheet, sheetToJson, sheetToCsv } from 'modern-xlsx';
// Array of arrays → rows
const rows = aoaToSheet([['Name', 'Age'], ['Alice', 30]]);
// JSON → rows
const rows = jsonToSheet([{ name: 'Alice', age: 30 }]);
// Rows → JSON
const data = sheetToJson(ws.rows);
// Rows → CSV
const csv = sheetToCsv(ws.rows);

Auto Filter

ws.autoFilter = 'A1:B3';

Page Setup

ws.pageSetup = {
 orientation: 'landscape',
 paperSize: 1,
 fitToWidth: 1,
 fitToHeight: 0,
};

Sheet Protection

ws.sheetProtection = {
 sheet: true,
 selectLockedCells: false,
 selectUnlockedCells: false,
};

Date Handling

import { dateToSerial, serialToDate, isDateFormatCode } from 'modern-xlsx';
dateToSerial({ year: 2026, month: 3, day: 1 }); // 46113
serialToDate(46113); // { year: 2026, month: 3, day: 1 }
isDateFormatCode('yyyy-mm-dd'); // true

Cell Reference Utilities

import { columnToLetter, letterToColumn, decodeCellRef, encodeCellRef } from 'modern-xlsx';
columnToLetter(1); // 'A'
letterToColumn('A'); // 1
decodeCellRef('B3'); // { row: 2, col: 2 }
encodeCellRef({ row: 2, col: 2 }); // 'B3'

Browser Download

import { writeBlob } from 'modern-xlsx';
const blob = writeBlob(wb);
const url = URL.createObjectURL(blob);
const a = document.createElement('a');
a.href = url;
a.download = 'output.xlsx';
a.click();
URL.revokeObjectURL(url);