The File Extensions Database


._XLSX File Extension

  • Category: Spreadsheet Files
  • Format: Zip

What is an ._XLSX file?

._XLSX is Renamed Microsoft Excel Open XML Spreadsheet

An _XLSX file is a Microsoft Excel spreadsheet file renamed from ".xlsx" to "._xlsx". It may have been renamed purposely or accidentally by a user or by a program. _XLSX files contain the same contents of an .XLSX file, which may include one or more worksheets that consist of cells arranged in a grid of rows and columns.

You can rename an _XLSX file by changing the "._xlsx" extension to ".xlsx". After renaming the file, you can open the XLSX file with a variety of programs, such as Microsoft Excel, LibreOffice Calc, and Apple Numbers.

_XLSX files may be created by email programs, specifically Windows Live Mail, when sending XLSX files via email. Windows Live Mail may rename the files if the filename ends with a "." before the "." in the extension. For example, sample..xlsx is changed to sample._xlsx by the email program. This also commonly occurs with .DOC, .DOCX, and .XLS files.

NOTE: XLSX files are typically created by Microsoft Excel. However, they may also be created using another spreadsheet program, such as LibreOffice Calc or Apple Numbers.

How to solve problems with _XLSX files

  • Associate the _XLSX file extension with the correct application. On :
    Windows: Right click on any _XLSX file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *._XLSX files". Mac: Right click (or Ctrl-click) the _XLSX file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
  • Update your software that should actually open ._XLSX is Renamed Microsoft Excel Open XML Spreadsheet. Because only the current version supports the latest _XLSX file format. Search, therefore, e.g. on the N/A manufacturer website after an available ._XLSX is Renamed Microsoft Excel Open XML Spreadsheet update.
  • To make sure that your _XLSX file is not corrupted or virus-infected, get the file again and scan it with antivirus software.