---
title: Bun
pagination_prev: getting-started/index
pagination_next: getting-started/examples/index
sidebar_position: 7
sidebar_custom_props:
summary: Load NodeJS-style modules using CommonJS or ESM
---
import current from '/version.js';
import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';
import CodeBlock from '@theme/CodeBlock';
Package tarballs are available on https://cdn.sheetjs.com.
{"https://cdn.sheetjs.com/xlsx-" + current + "/xlsx-" + current + ".tgz"} is the URL for version {current}
:::caution Bun support is considered experimental.
Great open source software grows with user tests and reports. Any issues should
be reported to the Bun project for further diagnosis.
:::
## Installation
Tarballs can be directly installed with `bun install`:
{`\
bun rm xlsx
bun install https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz`}
:::tip pass
[Watch the repo](https://git.sheetjs.com/SheetJS/sheetjs) or subscribe to the
[RSS feed](https://git.sheetjs.com/sheetjs/sheetjs/tags.rss) to be notified when
new versions are released!
:::
### Vendoring
For general stability, "vendoring" modules is the recommended approach:
0) Remove any existing dependency on a project named `xlsx`:
```bash
bun rm xlsx
```
Download the tarball (xlsx-{current}.tgz) for the desired version. The current version is available at {"https://cdn.sheetjs.com/xlsx-" + current + "/xlsx-" + current + ".tgz"}
2) Create a `vendor` subfolder at the root of your project and move the tarball
to that folder. Add it to your project repository.
3) Install the tarball:
{`\
bun install file:vendor/xlsx-${current}.tgz`}
The package will be installed and accessible as `xlsx`.
## Usage
The package supports CommonJS `require` and ESM `import` module systems.
:::info pass
**It is strongly recommended to use CommonJS in Bun.**
:::
### CommonJS `require`
By default, the module supports `require` and it will automatically add support
for encodings, streams and file system access:
```js
const { readFile } = require("xlsx");
const wb = readFile("pres.numbers"); // works!
```
:::caution pass
In the BunJS REPL, `require` incorrectly loads the ESM build.
:::
### ESM `import`
When importing the library using ESM `import` statements, the native NodeJS
modules are not loaded. They must be added manually:
```js
import * as XLSX from 'xlsx';
/* load 'fs' for readFile and writeFile support */
import * as fs from 'fs';
XLSX.set_fs(fs);
/* load 'stream' for stream support */
import { Readable } from 'stream';
XLSX.stream.set_readable(Readable);
/* load the codepage support library for extended support with older formats */
import * as cpexcel from 'xlsx/dist/cpexcel.full.mjs';
XLSX.set_cptable(cpexcel);
```
## Bundling
For server-side scripts, `bun build` can pre-optimize dependencies. The Bun
builder requires a proper `package.json` that includes the SheetJS dependency.
:::note Tested Deployments
This demo was last tested in the following deployments:
| Architecture | BunJS | Date |
|:-------------|:---------|:-----------|
| `darwin-x64` | `1.1.4` | 2024-04-19 |
| `win10-x64` | `1.1.4` | 2024-04-19 |
| `win11-x64` | `1.1.22` | 2024-08-11 |
| `linux-x64` | `1.1.4` | 2024-04-25 |
:::
0) Create a new project:
```bash
mkdir sheetjs-bun-dle
cd sheetjs-bun-dle
echo "{}" > package.json
```
:::caution pass
The PowerShell file redirect will use the `UTF-16 LE` encoding. Bun does not
support the encoding and will fail to install the package:
```
bun add v1.1.22-canary.96 (df33f2b2)
1 | ��{}
^
error: Unexpected ��
```
The file must be resaved in UTF8 (without BOM) or ASCII.
0) Open `package.json` in VSCodium.
The current encoding is displayed in the lower-right corner:
1) Click the displayed encoding.
2) In the "Select Action" popup, select "Save with Encoding"
3) In the new list, select `UTF-8 utf8`:
VSCodium will automatically re-save the file.
:::
1) Install the SheetJS package tarball:
{`\
bun install https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz`}
2) Save the following script to `SheetJSBun.js`:
```js title="SheetJSBun.js"
// highlight-next-line
import * as XLSX from 'xlsx';
// highlight-next-line
import * as fs from 'fs';
// highlight-next-line
XLSX.set_fs(fs);
/* fetch JSON data and parse */
const url = "https://docs.sheetjs.com/executive.json";
const raw_data = await (await fetch(url)).json();
/* filter for the Presidents */
const prez = raw_data.filter(row => row.terms.some(term => term.type === "prez"));
/* sort by first presidential term */
prez.forEach(row => row.start = row.terms.find(term => term.type === "prez").start);
prez.sort((l,r) => l.start.localeCompare(r.start));
/* flatten objects */
const rows = prez.map(row => ({
name: row.name.first + " " + row.name.last,
birthday: row.bio.birthday
}));
/* generate worksheet and workbook */
const worksheet = XLSX.utils.json_to_sheet(rows);
const workbook = XLSX.utils.book_new();
XLSX.utils.book_append_sheet(workbook, worksheet, "Dates");
/* fix headers */
XLSX.utils.sheet_add_aoa(worksheet, [["Name", "Birthday"]], { origin: "A1" });
/* calculate column width */
const max_width = rows.reduce((w, r) => Math.max(w, r.name.length), 10);
worksheet["!cols"] = [ { wch: max_width } ];
/* create an XLSX file and try to save to Presidents.xlsx */
XLSX.writeFile(workbook, "Presidents.xlsx");
```
3) Bundle the script with `bun build`:
```bash
bun build --target=bun SheetJSBun.js --outfile=app.js
```
This procedure will generate `app.js`.
4) Remove the module artifacts and original script:
```bash
rm package.json bun.lockb SheetJSBun.js
rm -rf ./node_modules
```
:::note pass
PowerShell does not support `rm -rf`. Instead, each file must be removed:
```powershell title="Windows Powershell commands"
rm package.json
rm bun.lockb
rm SheetJSBun.js
rm .\\node_modules -r -fo
```
:::
At this point, `app.js` will be the only file in the project folder.
5) Run the script:
```bash
bun app.js
```
If the script succeeded, the file `Presidents.xlsx` will be created. That file
can be opened in a spreadsheet editor.