sheetjs_sheetjs/docbits/81_writeopts.md

Writing Options

The exported write and writeFile functions accept an options argument:

Option Name	Default	Description
type		Output data encoding (see Output Type below)
cellDates	false	Store dates as type d (default is n)
bookSST	false	Generate Shared String Table **
bookType	"xlsx"	Type of Workbook (see below for supported formats)
sheet	""	Name of Worksheet for single-sheet formats **
compression	false	Use ZIP compression for ZIP-based formats **

• bookSST is slower and more memory intensive, but has better compatibility with older versions of iOS Numbers
• The raw data is the only thing guaranteed to be saved. Formulae, formatting, and other niceties may not be serialized (pending CSF standardization)
• cellDates only applies to XLSX output and is not guaranteed to work with third-party readers. Excel itself does not usually write cells with type d so non-Excel tools may ignore the data or blow up in the presence of dates.

Supported Output Formats

For broad compatibility with third-party tools, this library supports many output formats. The specific file type is controlled with bookType option:

bookType	file ext	container	sheets	Description
xlsx	.xlsx	ZIP	multi	Excel 2007+ XML Format
xlsm	.xlsm	ZIP	multi	Excel 2007+ Macro XML Format
xlsb	.xlsb	ZIP	multi	Excel 2007+ Binary Format
ods	.ods	ZIP	multi	OpenDocument Spreadsheet
biff2	.xls	none	single	Excel 2.0 Worksheet format
fods	.fods	none	multi	Flat OpenDocument Spreadsheet
csv	.csv	none	single	Comma Separated Values

• compression only applies to formats with ZIP containers.
• Formats that only support a single sheet require a sheet option specifying the worksheet. If the string is empty, the first worksheet is used.

Output Type

The type argument for write mirrors the type argument for read:

type	output
"base64"	string: base64 encoding of the file
"binary"	string: binary string (n-th byte is data.charCodeAt(n))
"buffer"	nodejs Buffer
"file"	string: name of file to be written (nodejs only)