**Read and write styled `.xlsx` files in the browser and Node.js, without shipping ExcelJS or SheetJS.**
Import a class and your bundler ships only that part: the writer adds 12.9 KB min+gzip.
[](https://kevinarce98.github.io/excel-bridge/)
[](https://www.npmjs.com/package/excel-bridge)
[](#bundle-size)
[](https://github.com/KevinArce98/excel-bridge/actions)
[](https://www.npmjs.com/package/excel-bridge)
[](./LICENSE)
[Live Demo](https://kevinarce98.github.io/excel-bridge/) · [Quick Start](#quick-start) · [Why excel-bridge?](#why-excel-bridge) · [Bundle size](#bundle-size) · [Guide](#guide) · [API Reference](#api-reference) · [Compatibility](#compatibility)
---
## Highlights
- **Small and tree-shakeable.** `ExcelWriter` adds 12.9 KB min+gzip. Import only the class you need ([sizes](#bundle-size)). ESM and CJS builds.
- **Read and write.** Cell styles (fill, font, **per-side borders**, alignment, number formats), formulas with optional cached results, dates, merged cells, freeze panes, column widths, **row heights**, hidden rows and columns, **conditional formatting**, data validation, **autofilters**, **hyperlinks**, hidden sheets and multi-sheet workbooks.
- **One API for the browser and Node.js.** `Blob` and `File` in the browser, `Uint8Array` in Node.js (a `Buffer` is one). Reading and writing buffers is synchronous; reading a `File` and streaming are async.
- **TypeScript-first.** Complete types and IntelliSense for every public export.
- **Built for large exports.** A streaming writer produces million-row files from sync or async iterables, so the rows never all live in memory at once.
- **Edit what you wrote.** `Workbook` loads, edits and saves files the library can model ([what a round trip keeps](#what-a-round-trip-keeps)).
- **Two direct dependencies.** `fflate` for zip and `fast-xml-parser` for reading. The writer bundles no parser code.
- **Signed releases.** Every version is published to npm with [provenance](https://docs.npmjs.com/generating-provenance-statements).
## Installation
```bash
npm install excel-bridge
```
```bash
pnpm add excel-bridge
```
```bash
yarn add excel-bridge
```
> **[Try the live demo →](https://kevinarce98.github.io/excel-bridge/)** Build a styled workbook and download it, or drop in an `.xlsx` and see it parsed, all in your browser. Prefer Node.js? Run it on [RunKit](https://npm.runkit.com/excel-bridge).
## Quick Start
Import the class you need: `ExcelWriter`, `ExcelReader` or [`Workbook`](#high-level-workbook-api).
Your bundler ships only that part of the library ([sizes](#bundle-size)).
### Write a workbook
```typescript
import { ExcelWriter } from 'excel-bridge';
const writer = new ExcelWriter();
const header = { bold: true, background: '#4472C4', color: '#FFFFFF' };
const sheet = {
data: [
['Name', 'Age', 'City'],
['John', 25, 'New York'],
['Jane', 30, 'Los Angeles'],
],
styles: { '0-0': header, '0-1': header, '0-2': header },
options: { name: 'People', freezePane: { row: 1 }, autoWidth: true },
};
// Browser: get a Blob to download
const blob = writer.createWorkbook([sheet]);
const url = URL.createObjectURL(blob);
// Node.js: get a Uint8Array to write to disk
import fs from 'node:fs';
fs.writeFileSync('output.xlsx', writer.createWorkbookBuffer([sheet]));
```
`createWorkbookBuffer` returns a plain `Uint8Array`, not a `Buffer`. Frameworks that look for a
`Buffer` need a wrapper, for example `res.send(Buffer.from(bytes))` in Express 4.
### Read a workbook
```typescript
import { ExcelReader } from 'excel-bridge';
const reader = new ExcelReader();
// Node.js: from a Buffer or Uint8Array (synchronous)
import fs from 'node:fs';
const workbook = reader.parseFromBuffer(fs.readFileSync('data.xlsx'));
// Browser: from a File, such as the one an