web-xlsx

📖 This document is an AI-generated translation. The authoritative source is the Japanese version: README.ja.md.

A TypeScript xlsx read/write library that works in both browsers and Node.

See the demo page here.

Features

• Small bundle with zero dependencies
• Parse into typed rows from a schema
• Use the same schema for read and write
• Unified return values via a Result type

Installation

npm install web-xlsx
pnpm add web-xlsx
bun add web-xlsx

• ESM only
• Node.js 22 or later
• Browsers: current versions with deflate-raw support

Quick Start

For details on each API and its options, see docs/api/.

read

import { parseFile, defineSchema } from "web-xlsx";

const schema = defineSchema({
  Name: { prop: "name", type: "string", required: true },
  Age: { prop: "age", type: "number" },
  HireDate: { prop: "hireDate", type: "date" },
});

const result = await parseFile(file, { schema });
if (result.ok) {
  console.log(result.data);
  // { name: string; age: number|null; hireDate: Date|null }[]
}

write

import { build } from "web-xlsx/write";

// Write using the same schema as read (the return value is the same Result as read)
const written = await build(result.data, { schema });
if (written.ok) {
  console.log(written.data); // Uint8Array
}

Limitations

• read: formulas are not evaluated
• read: rejects reading when the header has duplicate column names
• read: a type: 'number' column receiving a date-formatted cell yields a "not a number" error (use type: 'date' for dates)
• write: only a single sheet with a plain table
• write: extremely large or small numbers may render in exponential notation
• read/write: dates are treated as local time by default
• read/write: a Date before 1900-01-01 becomes a negative serial value and shows as #### in Excel

Not supported

• read: bulk reading of multiple sheets
• read: expanding merged cells
• read: ZIP64 and encrypted workbooks
• read/write: streaming

License

MIT