Sample XLS File Download

XLS is the legacy binary spreadsheet format from Excel versions before 2007, when Microsoft switched to the XML-based XLSX. It stores data in a proprietary binary structure — rows, columns, formulas, and formatting all packed into a format that requires specific parsing logic to read correctly.

You'll mostly encounter XLS today in older exports from legacy systems, older accounting software, or archives that predate the 2007 format switch. Modern Excel, LibreOffice Calc, and Google Sheets can all still open it, but some spreadsheet libraries only implement full support for XLSX and treat XLS as an afterthought.

If your import pipeline needs to handle both formats, the file below is a real XLS binary you can use to catch gaps before a customer's older export file exposes them in production.