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XLSX and export

Register the optional XLSX backend and choose table or workbook interchange deliberately.

CSV and TSV remain core-only. XLSX is optional so normal grid and framework bundles do not pull spreadsheet-file dependencies into their initial graph.

Install the optional XLSX backend
bun add @sheetwrite/xlsx

Register it once before invoking grid XLSX actions or the core workbook/table functions:

Register and export
import "@sheetwrite/xlsx/register";


await grid.exportXlsx("sales.xlsx");

Table interchange

toXlsxTable and fromXlsxTable exchange the active rectangular table. They deliberately reduce scope and fidelity — one sheet, synthesized headers, resolved scalars instead of formula source — and, like the workbook APIs, they materialize the complete file in memory rather than streaming it. CSV output is UTF-8 with a BOM and CRLF line endings and prefixes injection-sensitive leading characters in string values.

Workbook interchange

toXlsxWorkbook and fromXlsxWorkbook preserve supported worksheets, formula source, styles, merges, dimensions, frozen panes, names, and Sheetwrite metadata. Unsupported Excel features may be flattened or dropped and are reported through the structured onWarning callback (XlsxWorkbookWarning); callers must surface warnings when fidelity matters. Both directions build the complete workbook representation in memory; budget accordingly for large files.

Resource limits

Every table and workbook path shares one resource contract, XlsxWorkbookOptions:

  • maxCells bounds logical accepted cells and defaults to 1_000_000;
  • resourceLimits overrides the remaining bounded dimensions, checked before decompression and allocation: input bytes (32 MiB), output bytes (128 MiB), archive entries (1,024), per-entry uncompressed bytes (64 MiB), total uncompressed bytes (256 MiB), compression ratio (×100), sheets (256), rows per sheet (1,048,576), columns per sheet (16,384), merges (100,000), shared strings (1,000,000), style records (65,536), XML elements (2,000,000), XML depth (64), XML attributes per element (128), and XML text bytes (16 MiB);
  • signal aborts between bounded codec stages.

Crossing any bound rejects with a typed XlsxResourceError naming the resource, limit, and observed value — before the codec allocates unsafe data. The defaults are exported as DEFAULT_XLSX_RESOURCE_LIMITS.

The optional package implements a bounded OOXML subset internally over one audited compression primitive (fflate). Load @sheetwrite/xlsx/register on the path that needs XLSX rather than in every application entry.