You can open .xlsx files with any spreadsheet program that supports the Excel format, the most common being Microsoft Excel itself.

Main options to open .xlsx files

  • Microsoft Excel – The native program for .xlsx spreadsheets, available on Windows, macOS, web, iOS, and Android.
  • Free office suites – Programs like WPS Office or other Excel-compatible viewers let you open, view, and often edit .xlsx files without needing Excel.
  • Dedicated XLSX viewers – Standalone viewer tools (for example, SysTools XLSX Viewer or similar utilities) let you open and read .xlsx files even if Excel is not installed.
  • Online viewers – Many web-based services allow you to upload and view .xlsx files directly in the browser.

Simple example

If someone emails you a file named report.xlsx and you have Microsoft Office installed, just double‑click it and it will open in Excel.

TL;DR: The standard program used to open .xlsx files is Microsoft Excel, but you can also use free Excel-compatible office suites, dedicated viewers, or online tools.