XLS files are spreadsheet files created by Microsoft Office Excel. An Excel spreadsheet can contain anything from images and plain text to graphs and tables and can be opened using Excel.

Learn how to convert CSV to Excel including XLS and XLSX formats using command line interface in Windows 11/10, the easy way.

How to convert an XLS file to CSV Let’s say you have the file clients.xlsx and you need it converted to clients.csv to be then uploaded as a client list in your new CRM tool.