What Is an XLSX File?

A file with the XLSX file extension is a Microsoft Excel Open XML Format Spreadsheet file.

It’s a ZIP-compressed, XML-based spreadsheet file created by Microsoft Excel version 2007 and later.

Image of a weekly schedule planner in Excel

Lifewire

Spreadsheet files made in earlier versions of Excel are saved in theXLSformat.

Excel files that support macros areXLSMfiles.

Going this route requires you to upload the XLSX file to the website before you might make any changes.

Screenshot showing how to convert XLSX files in Excel in Windows 8

Converting an XLSX File to CSV With Excel.

This is normally done through theFile>Save asmenu option.

TheF12key should also work to get to theSave Aswindow.

TinyWow can split an Excel fileif you want the XLSX file to end up as multiple files.

Screenshot of an error in Windows 8 while trying to open a file that doesn’t have a program associated with it

Still Can’t pop launch the File?

Windows Media Player opens LSX files.

XLRis another one that’s easy to mix up for an Excel file.

If you’re able to’t pop kick open the file, re-read the extension and research it online.