Convert a 2D array to xls-compatible CSV, TSV, or XLSX file.

include csv4xls script, and use:

// always catch exception in case XLSX fails to convert.
try {
  // Default: XLSX
  ret = csv4xls.toBlob([[1,2,3],[4,5,6]])
  
  // Tab-separated (TSV) / comma-separated (CSV)
  ret = csv4xls.toBlob([[1,2,3],[4,5,6]], {format: 'tsv'})
  ret = csv4xls.toBlob([[1,2,3],[4,5,6]], {format: 'csv'})
  
  // XLSX (default; uses the builtin 0-dependency writer)
  ret = csv4xls.toBlob([[1,2,3],[4,5,6]], {format: 'xlsx'})
  
  // XLSX keeping native number / boolean types
  ret = csv4xls.toBlob([[1,2,3],[4,5,6]], {format: 'xlsx', forceText: false})
  
  // XLSX via SheetJS instead of the builtin writer (requires global XLSX)
  ret = csv4xls.toBlob([[1,2,3],[4,5,6]], {format: 'xlsx', engine: 'sheetjs'})
  
  // Download with options
  csv4xls.download([[1,2,3],[4,5,6]], "mydata") // Will download as mydata.xlsx
  csv4xls.download([[1,2,3],[4,5,6]], "mydata", {format: 'csv'}) // Will download as mydata.csv
  csv4xls.download([[1,2,3],[4,5,6]], "mydata", {format: 'tsv'}) // Will download as mydata.tsv
} catch(e) {
}

csv4xls provides following APIs:

• toString(data, delimiter = '\t') - convert given 2D array to CSV/TSV in String format.
• toArray(data, delimiter = '\t') - convert given 2D array to an xls-compatible CSV/TSV file in the returned Uint8Array.
• toXlsx(data, options = {forceText: true, sheetName: 'Sheet1', engine: 'builtin'}) - convert given 2D array to xlsx file bytes in a Uint8Array.
  • Uses the builtin, dependency-free writer. Pass engine: 'sheetjs' to use the global XLSX (SheetJS) library instead.
• toWorkbook(data, options = {forceText: false}) - convert given 2D array to a SheetJS workbook object (requires XLSX library).
• toBlob(data, options = {delimiter: '\t', format: 'auto', forceText: true}) - convert data to blob with specified format.
  • If format is 'xlsx', returns XLSX blob
  • If format is 'html', returns HTML table as blob with MIME type text/html
  • If format is 'xls-html', returns HTML table with BOM as blob with MIME type application/vnd.ms-excel
    • Uses mso-number-format:'\@' style to prevent Excel from changing formats
  • If format is 'auto' (default), returns XLSX. Use 'csv' / 'tsv' for delimiter-separated output
  • HTML options can be passed via options.html object (see toHtml for available options)
  • If forceText is true (default for XLSX), all cells are written as text so Excel won't reinterpret values like "00123". Set to false to keep native number / boolean types
  • options.sheetName sets the worksheet name (default 'Sheet1')
• toHref(data, options = {delimiter: '\t', format: 'auto', forceText: true}) - same as toBlob but return a corresponding object url.
• toHtml(data, options = {}) - convert given 2D array to HTML table format.
  • options.tableClass - CSS class for the table (default: 'csv4xls-table')
  • options.cellStyle - Whether to apply mso-number-format:'\@' style to cells to prevent Excel from changing formats (default: true)
  • options.headerRow - Whether to treat the first row as a header row using <th> tags (default: false)
• download(data, name = "data", options = {delimiter: '\t', format: 'auto', forceText: true}) - trigger file download
  • If format is 'xlsx', file extension will be .xlsx
  • If format is 'html', file extension will be .html
  • If format is 'xls-html', file extension will be .xls (HTML with BOM that Excel can open)
  • If format is 'auto' (default), uses XLSX
  • If using CSV/TSV: delimiter ',' → .csv, delimiter '\t' → .tsv

• CSV/TSV format only works with Excel if file is opened directly. Doesn't work when importing with text import wizard.
• Default format is xlsx. For CSV/TSV output, set format (or delimiter) explicitly; default delimiter is tab ('\t').
• File extension and MIME type are automatically set based on the format and delimiter:
  • XLSX → .xlsx with MIME type application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
  • Comma (,) → .csv with MIME type text/csv
  • Tab (\t) → .tsv with MIME type text/tab-separated-values
• XLSX output is generated by a builtin writer with zero dependencies. It writes a minimal package (inline strings, no styling, STORE-mode zip), which Excel opens directly.
• SheetJS is only used when engine: 'sheetjs' is given explicitly, in which case the global XLSX must be available.
• When format is set to 'auto' (default), XLSX is used.

When using in Nodejs environment, version 18+ is required for Blob support which is used in toBlob function. Also, download api trigger download via link clicking thus it's also a frontend-only feature.

MIT