XLSX File

Microsoft Excel Workbook (.xlsx)

What is a XLSX file?

An XLSX file is a Microsoft Excel spreadsheet workbook. It stores worksheets with rows and columns, formulas, charts, tables, and formatting. XLSX is a zipped package of XML files (similar to DOCX), which helps with structure and compatibility.

Common uses

Budgets, invoices, and financial tracking
Data analysis with formulas and charts
Tables, schedules, and reports
Import/export for business tools and CRMs
Sharing structured data with colleagues

How to open a XLSX file

Windows: Microsoft Excel, LibreOffice Calc
macOS: Excel, Numbers (import), LibreOffice Calc
Online: Google Sheets or Excel for the web
Tip: If formulas look wrong, check regional settings (decimal/comma)

Common problems

Broken formulas due to app differences
Macros won’t run (XLSX doesn’t store macros; that’s XLSM)
Formatting shifts when imported into other tools
Large files can be slow with many formulas/charts
File corruption after crash or interrupted save

History

XLSX was introduced with Microsoft Office 2007 as part of the Office Open XML standard. It replaced the older .xls format and became the default Excel workbook type because it’s more structured, easier to recover, and widely supported.