Cellify

A lightweight, zero-dependency* spreadsheet library for JavaScript/TypeScript.
Create, read, and manipulate Excel files with ease.

📚 Documentation • 🎮 Live Demo • 📦 npm

*Only dependency is fflate for ZIP compression

Features

Excel Import/Export - Full .xlsx support with styles, formulas, merged cells
CSV Import/Export - Auto-detection of delimiters and data types
WASM-Accelerated - Optional Rust/WebAssembly parser for 10-50x faster imports
Complete Styling - Fonts, fills, borders, alignment, number formats
Cell Merging - With overlap detection and validation
Formulas - Store and preserve formulas (evaluation coming soon)
Cell Comments - Add comments with author information
Hyperlinks - URLs, email links, and internal cell references
Freeze Panes - Lock rows/columns for scrolling
Auto Filters - Enable filtering on data ranges
Type-Safe - Built with TypeScript from the ground up
Universal - Works in Node.js and browsers
Accessible - Built-in a11y helpers for screen readers

Demo

Try the interactive demo to test import/export functionality:

npm run demo

The demo includes:

Cell editing - Double-click or press Enter to edit cells
Right-click context menu - Copy, cut, paste, formatting, comments
Keyboard shortcuts - Ctrl+C/X/V, Ctrl+B/I, Ctrl+Z, arrow keys
Column/row selection - Click headers to select entire columns or rows
Column filters - Filter data by clicking the filter button in headers
Cell comments - Add, edit, and delete comments via context menu

Installation

npm install cellify

Quick Start

import { Workbook, workbookToXlsx } from 'cellify';

// Create a workbook
const workbook = new Workbook();
const sheet = workbook.addSheet('Sales Data');

// Set values
sheet.cell('A1').value = 'Product';
sheet.cell('B1').value = 'Revenue';
sheet.cell('A2').value = 'Widget';
sheet.cell('B2').value = 1500;

// Apply styles
sheet.cell('A1').style = {
  font: { bold: true, color: '#FFFFFF' },
  fill: { type: 'pattern', pattern: 'solid', foregroundColor: '#4472C4' },
};

// Export to Excel
const xlsxBuffer = workbookToXlsx(workbook);
// Save or send xlsxBuffer as .xlsx file

Excel (.xlsx) Export

Create Excel files with full styling support:

import { Workbook, workbookToXlsx, workbookToXlsxBlob } from 'cellify';

const workbook = new Workbook();
workbook.title = 'Sales Report';
workbook.author = 'Cellify';

const sheet = workbook.addSheet('Q4 Sales');

// Headers with styling
const headers = ['Product', 'Units', 'Price', 'Total'];
headers.forEach((header, i) => {
  const cell = sheet.cell(0, i);
  cell.value = header;
  cell.style = {
    font: { bold: true, size: 12, color: '#FFFFFF' },
    fill: { type: 'pattern', pattern: 'solid', foregroundColor: '#2F5496' },
    alignment: { horizontal: 'center' },
    borders: {
      bottom: { style: 'medium', color: '#000000' },
    },
  };
});

// Data rows
const data = [
  ['Laptop', 150, 999.99],
  ['Mouse', 500, 29.99],
  ['Keyboard', 300, 79.99],
];

data.forEach((row, rowIndex) => {
  row.forEach((value, colIndex) => {
    sheet.cell(rowIndex + 1, colIndex).value = value;
  });
  // Formula for total
  sheet.cell(rowIndex + 1, 3).setFormula(`B${rowIndex + 2}*C${rowIndex + 2}`);
});

// Set column widths
sheet.setColumnWidth(0, 15); // Product
sheet.setColumnWidth(1, 10); // Units
sheet.setColumnWidth(2, 12); // Price
sheet.setColumnWidth(3, 12); // Total

// Freeze header row
sheet.freeze(1, 0);

// Enable auto filter
sheet.setAutoFilter('A1:D4');

// Export
const buffer = workbookToXlsx(workbook); // Uint8Array for Node.js
const blob = workbookToXlsxBlob(workbook); // Blob for browsers

Excel (.xlsx) Import

Read existing Excel files:

import { xlsxToWorkbook, xlsxBlobToWorkbook } from 'cellify';

// From Uint8Array (Node.js)
const buffer = fs.readFileSync('report.xlsx');
const { workbook, stats, warnings } = xlsxToWorkbook(new Uint8Array(buffer));

console.log(`Imported ${stats.sheetCount} sheets, ${stats.totalCells} cells`);

// Access data
const sheet = workbook.getSheetByIndex(0);
console.log(sheet.cell('A1').value); // Read cell value
console.log(sheet.cell('B2').formula); // Read formula

// From Blob (browsers)
const file = document.getElementById('fileInput').files[0];
const result = await xlsxBlobToWorkbook(file);

// Import options
const { workbook } = xlsxToWorkbook(buffer, {
  sheets: ['Sheet1', 'Summary'], // Import specific sheets
  importFormulas: true,          // Preserve formulas
  importStyles: true,            // Import cell styles
  importMergedCells: true,       // Import merged cells
  importFreezePanes: true,       // Import freeze panes
  maxRows: 1000,                 // Limit rows (0 = unlimited)
  maxCols: 50,                   // Limit columns (0 = unlimited)
  onProgress: (phase, current, total) => {
    console.log(`${phase}: ${current}/${total}`);
  },
});

Performance: WASM Acceleration

Cellify includes an optional WebAssembly parser built with Rust that provides 10-50x faster XLSX imports for large files.

import { initXlsxWasm, isXlsxWasmReady, xlsxToWorkbook } from 'cellify';

// Initialize WASM at app startup (optional but recommended)
await initXlsxWasm();

// Check if WASM is available
if (isXlsxWasmReady()) {
  console.log('Using WASM-accelerated parser');
}

// Import will automatically use WASM if available
const { workbook } = xlsxToWorkbook(buffer);

// Disable WASM for specific imports if needed
const { workbook } = xlsxToWorkbook(buffer, { useWasm: false });

Performance Comparison

File Size	JS Parser	WASM Parser	Speedup
10K cells	~500ms	~50ms	10x
100K cells	~5s	~200ms	25x
1M cells	~50s	~2s	25x

Building WASM (Optional)

The WASM module is pre-built and included. To rebuild from source:

# Install Rust
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# Add WASM target
rustup target add wasm32-unknown-unknown

# Install wasm-pack
cargo install wasm-pack

# Build WASM module
npm run build:wasm

CSV Import/Export

import { sheetToCsv, csvToWorkbook } from 'cellify';

// Export to CSV
const csv = sheetToCsv(sheet);
// "Product,Units,Price,Total\r\nLaptop,150,999.99,149998.5"

// Import from CSV (auto-detects delimiter)
const { workbook } = csvToWorkbook(csvString);

// With options
const csv = sheetToCsv(sheet, {
  delimiter: ';',
  includeHeaders: true,
  dateFormat: 'YYYY-MM-DD',
});

Cell Styling

// Font styling
cell.style = {
  font: {
    name: 'Arial',
    size: 14,
    bold: true,
    italic: true,
    underline: 'single', // 'single' | 'double'
    strikethrough: true,
    color: '#FF0000',
  },
};

// Fill/background
cell.style = {
  fill: {
    type: 'pattern',
    pattern: 'solid',
    foregroundColor: '#FFFF00',
  },
};

// Borders
cell.style = {
  borders: {
    top: { style: 'thin', color: '#000000' },
    right: { style: 'medium', color: '#000000' },
    bottom: { style: 'thick', color: '#000000' },
    left: { style: 'dashed', color: '#000000' },
  },
};

// Alignment
cell.style = {
  alignment: {
    horizontal: 'center', // 'left' | 'center' | 'right'
    vertical: 'middle',   // 'top' | 'middle' | 'bottom'
    wrapText: true,
    textRotation: 45,     // -90 to 90 degrees
  },
};

// Number format
cell.style = {
  numberFormat: {
    formatCode: '#,##0.00', // Excel format codes
  },
};

// Apply style to range
sheet.applyStyle('A1:D1', {
  font: { bold: true },
  fill: { type: 'pattern', pattern: 'solid', foregroundColor: '#E0E0E0' },
});

Cell Merging

// Merge cells using A1 notation
sheet.mergeCells('A1:D1'); // Merge A1 through D1

// Merge cells using coordinates
sheet.mergeCells({ startRow: 0, startCol: 0, endRow: 2, endCol: 2 });

// Check if cell is part of a merge
const cell = sheet.cell('B1');
if (cell.isMergeMaster) {
  console.log('This is the top-left cell of a merge');
}
if (cell.isMerged) {
  console.log('This cell is merged into another cell');
}

// Unmerge cells
sheet.unmergeCells('A1:D1');

Row and Column Configuration

// Set column width (in characters)
sheet.setColumnWidth(0, 20);  // Column A = 20 characters wide
sheet.setColumnWidth('B', 15); // Column B = 15 characters

// Set row height (in points)
sheet.setRowHeight(0, 30); // Row 1 = 30 points tall

// Hide rows/columns
sheet.hideRow(5);
sheet.hideColumn('C');

// Get all column configs
sheet.columns.forEach((config, index) => {
  console.log(`Column ${index}: width=${config.width}`);
});

Freeze Panes

// Freeze first row (header)
sheet.freeze(1, 0);

// Freeze first column
sheet.freeze(0, 1);

// Freeze both (first row and first two columns)
sheet.freeze(1, 2);

Formulas

// Set a formula
sheet.cell('D2').setFormula('B2*C2');

// With or without leading '='
sheet.cell('D3').setFormula('=SUM(B2:B10)');

// Access formula text
const formula = sheet.cell('D2').formula;
console.log(formula.formula); // 'B2*C2'

// Note: Cellify stores formulas but doesn't evaluate them yet
// Excel will calculate values when the file is opened

Cell Comments

// Add a comment to a cell
sheet.cell('A1').setComment('This needs review', 'John Doe');

// Add comment without author
sheet.cell('B1').setComment('Important note');

// Access comment
const cell = sheet.cell('A1');
if (cell.comment) {
  console.log(cell.comment.text);   // 'This needs review'
  console.log(cell.comment.author); // 'John Doe'
}

// Clear comment
sheet.cell('A1').clearComment();
// or
sheet.cell('A1').comment = undefined;

Hyperlinks

sheet.cell('A1').value = 'Visit Google';
sheet.cell('A1').setHyperlink('https://google.com', 'Go to Google');

sheet.cell('A2').value = 'Contact Us';
sheet.cell('A2').setHyperlink('mailto:support@example.com');

sheet.cell('A3').value = 'Go to Summary';
sheet.cell('A3').setHyperlink('#Summary!A1', 'Jump to Summary sheet');

const cell = sheet.cell('A1');
if (cell.hyperlink) {
  console.log(cell.hyperlink.target);  // 'https://google.com'
  console.log(cell.hyperlink.tooltip); // 'Go to Google'
}

sheet.cell('A1').clearHyperlink();

Named Ranges

// Define a named range
workbook.addDefinedName('SalesData', 'Sheet1!$A$1:$D$100');

// Use in formulas
sheet.cell('E1').setFormula('SUM(SalesData)');

Workbook Properties

const workbook = new Workbook();

// Set metadata
workbook.title = 'Q4 Sales Report';
workbook.author = 'John Doe';
workbook.setProperties({
  subject: 'Quarterly Sales',
  company: 'Acme Corp',
  keywords: ['sales', 'q4', '2024'],
});

// These appear in Excel's File > Info panel

Accessibility

Cellify provides helpers for building accessible spreadsheet UIs:

import {
  getCellAccessibility,
  getAriaAttributes,
  announceNavigation,
} from 'cellify';

// Generate ARIA attributes for a cell
const a11y = getCellAccessibility(cell, sheet, {
  headerRows: 1,
  headerCols: 1,
});

const ariaProps = getAriaAttributes(a11y);
// { role: 'gridcell', 'aria-colindex': 2, 'aria-rowindex': 3, ... }

// Screen reader announcement
const announcement = announceNavigation(cell);
// { message: 'Cell B3, row 3, column 2, 1500', priority: 'polite' }

API Reference

Workbook

Method	Description
`addSheet(name?)`	Add a new sheet
`getSheet(name)`	Get sheet by name
`getSheetByIndex(index)`	Get sheet by index
`removeSheet(sheet)`	Remove a sheet
`renameSheet(old, new)`	Rename a sheet

Sheet

Method	Description
`cell(address)`	Get cell by A1 notation
`cell(row, col)`	Get cell by coordinates
`mergeCells(range)`	Merge cells in range
`unmergeCells(range)`	Unmerge cells
`setColumnWidth(col, width)`	Set column width
`setRowHeight(row, height)`	Set row height
`freeze(rows, cols)`	Freeze panes
`setAutoFilter(range)`	Enable auto filter
`applyStyle(range, style)`	Apply style to range

Cell

Property	Description
`value`	Cell value (string, number, boolean, Date)
`style`	Cell style object
`formula`	Formula object
`comment`	Cell comment with text and author
`hyperlink`	Hyperlink with target URL and tooltip
`address`	A1 notation address
`type`	Value type
`isMerged`	Is part of merge
`isMergeMaster`	Is top-left of merge

Format Functions

Function	Description
`workbookToXlsx(workbook)`	Export to Uint8Array
`workbookToXlsxBlob(workbook)`	Export to Blob
`xlsxToWorkbook(buffer)`	Import from Uint8Array
`xlsxBlobToWorkbook(blob)`	Import from Blob
`sheetToCsv(sheet)`	Export sheet to CSV
`csvToWorkbook(csv)`	Import CSV to workbook
`initXlsxWasm()`	Initialize WASM parser
`isXlsxWasmReady()`	Check if WASM is ready

Browser Usage

<script type="module">
import { Workbook, workbookToXlsxBlob } from 'cellify';

// Create workbook
const workbook = new Workbook();
const sheet = workbook.addSheet('Data');
sheet.cell('A1').value = 'Hello, Excel!';

// Download as file
const blob = workbookToXlsxBlob(workbook);
const url = URL.createObjectURL(blob);
const a = document.createElement('a');
a.href = url;
a.download = 'spreadsheet.xlsx';
a.click();
</script>

Supported Cell Types

Type	Example	Notes
String	`'Hello'`	Plain text
Number	`42`, `3.14`	Integers and decimals
Boolean	`true`, `false`
Date	`new Date()`	Converted to Excel serial
Formula	`'=SUM(A1:A10)'`	Stored, evaluated by Excel
Error	`'#VALUE!'`	Excel error values

Border Styles

Available border styles: thin, medium, thick, dashed, dotted, double, hair, dashDot, dashDotDot, mediumDashed, mediumDashDot, mediumDashDotDot, slantDashDot

Planned Features

Formula evaluation engine
Data validation (dropdowns, constraints)
Conditional formatting export
Charts (basic)

Contributing

See CONTRIBUTING.md for development setup and guidelines.

License

MIT - see LICENSE

Name		Name	Last commit message	Last commit date
Latest commit History 91 Commits
.github		.github
assets		assets
demo		demo
docs-site		docs-site
docs		docs
examples		examples
scripts		scripts
src		src
tests		tests
wasm		wasm
.gitignore		.gitignore
CHANGELOG.md		CHANGELOG.md
CONTRIBUTING.md		CONTRIBUTING.md
LICENSE		LICENSE
README.md		README.md
package-lock.json		package-lock.json
package.json		package.json
tsconfig.cjs.json		tsconfig.cjs.json
tsconfig.esm.json		tsconfig.esm.json
tsconfig.json		tsconfig.json
tsconfig.types.json		tsconfig.types.json
vitest.config.ts		vitest.config.ts

License

abdullahmujahidali/Cellify

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Cellify

Features

Demo

Installation

Quick Start

Excel (.xlsx) Export

Excel (.xlsx) Import

Performance: WASM Acceleration

Performance Comparison

Building WASM (Optional)

CSV Import/Export

Cell Styling

Cell Merging

Row and Column Configuration

Freeze Panes

Formulas

Cell Comments

Hyperlinks

Named Ranges

Workbook Properties

Accessibility

API Reference

Workbook

Sheet

Cell

Format Functions

Browser Usage

Supported Cell Types

Border Styles

Planned Features

Contributing

License

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