XLSX File Format: Excel Workbooks, Compatibility and Conversions

What is XLSX?

XLSX is the modern XML-based Microsoft Excel workbook format. It can store multiple worksheets, formulas, cell formatting, charts and other spreadsheet structures in a package of related files.

Common uses

• Financial models and calculations
• Lists, schedules and business reports
• Structured tables that need formulas or multiple worksheets

Advantages

• Supports multiple worksheets
• Stores formulas and structured cell data
• Broad compatibility with modern spreadsheet software
• More efficient and extensible than the older XLS format

Limitations

• Conversion to CSV removes workbook structure such as multiple sheets and most formatting
• Complex formulas, charts and macros may not survive every conversion
• Different spreadsheet applications can calculate or render some features differently

Compatible software

Microsoft Excel is the primary application. LibreOffice Calc, Google Sheets and other spreadsheet programs can generally work with XLSX.

When should you use it?

Choose XLSX when you need a full spreadsheet workbook with formulas, formatting or multiple sheets.

Consider another format: Use CSV when you only need a simple rectangular data table for import/export.