What is a .XLSX file?

A .XLSX file is a Microsoft Excel Open XML Spreadsheet associated with Documents. Zip-compressed XML spreadsheet format created by Microsoft Excel.

How do I open a .XLSX file on Windows or Mac?

You can open .XLSX files using Microsoft Excel 365, Google Sheets, LibreOffice Calc. If you do not have native software installed, you can use OpenAnyFile's free File Identifier or convert .XLSX to a standard format in your browser.

Is a .XLSX file safe to open?

This format carries a safety rating of Low Risk. Standard XLSX spreadsheets do not store macros (XLSM stores macros). Safe.

Can I convert a .XLSX file to other formats?

Yes! .XLSX can be converted to formats such as .CSV, .PDF directly in your web browser.

What should I do if a .XLSX file is corrupted or won't open?

If your .XLSX file displays an invalid header or signature error, check its magic bytes hex header (50 4B 03 04 (PK.. Zip archive)) using OpenAnyFile's Magic Byte Detector or follow our step-by-step file repair guide.

Documents • MIME: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

.XLSX – Microsoft Excel Open XML Spreadsheet

Zip-compressed XML spreadsheet format created by Microsoft Excel.

Primary Category Documents

MIME Type application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

Magic Bytes Signature 50 4B 03 04 (PK.. Zip archive)

Security Risk Rating Low Risk

Recommended Software to Open .XLSX

Microsoft Excel 365

windows, mac, android, ios • Commercial

Google Sheets

windows, mac, linux, android, ios • Free

LibreOffice Calc

windows, mac, linux • Free