XLSX files open in spreadsheet programs, most commonly Microsoft Excel or the free alternatives Google Sheets and LibreOffice Calc

An XLSX file is a spreadsheet — a grid of cells holding numbers, text, formulas, and charts. The file extension .xlsx tells your computer what program should open it. If you double-click an XLSX file and nothing happens, or the wrong program opens, you need to tell your computer which spreadsheet process to use. The fastest route depends on what you already have installed.

On Windows, Excel is the standard choice if you own it. On Mac, Excel works the same way. If you do not own Excel, Google Sheets (free, online) and LibreOffice Calc (free, downloadable) both open XLSX files without any loss of data for most everyday spreadsheets. The choice matters only if your file contains advanced Excel features like complex macros or pivot tables — those sometimes behave differently in other programs.

Key Takeaways

  • XLSX files are spreadsheets that open in Excel, Google Sheets, LibreOffice Calc, or other spreadsheet programs depending on what you have installed.
  • Double-clicking an XLSX file opens it in whatever program your computer has set as the default — you can change this default in your system settings.
  • Google Sheets opens XLSX files for free in a web browser and automatically saves your changes online.
  • LibreOffice Calc is a free downloadable program that works on Windows, Mac, and Linux and handles most XLSX files the same way Excel does.
  • If an XLSX file contains advanced Excel features like macros or complex formulas, opening it in a different program may cause those features to stop working.

Opening an XLSX file in Excel

If you own Microsoft Excel, the simplest method is to double-click the XLSX file. Excel should open automatically. If it does not, right-click the file, select "Open with", and choose Microsoft Excel from the list. On Mac, the steps are the same — right-click (or Control-click), then "Open with", then Excel.

If you want every XLSX file to open in Excel by default, right-click any XLSX file, select "Open with", then choose "Choose another app" (Windows) or "Other" (Mac). Find Excel in the list, check the box that says "Always use this app to open .xlsx files", and click Open. After that, double-clicking any XLSX file will go straight to Excel.

Opening an XLSX file in Google Sheets

Google Sheets is free and requires no installation — it runs in your web browser. Go to sheets.google.com, sign in with a Google account (create one free if you do not have one), and click the "+" button to start a new sheet. Then click "File", select "Open", and choose "Upload". Select your XLSX file from your computer. Google Sheets will convert it and open it in your browser.

Alternatively, you can upload the file directly from your computer. Right-click the XLSX file, select "Open with", then choose "Google Sheets" if it appears in the list. If it does not appear, select "More apps", search for "Google Sheets", and click it. Google Sheets will upload and open your file automatically. Any changes you make are saved online, so you do not have to remember to save manually.

Opening an XLSX file in LibreOffice Calc

LibreOffice Calc is a free spreadsheet program you read and install on your computer. Go to libreoffice.org, click "read", and select the version for your operating system (Windows, Mac, or Linux). Run the installer and follow the prompts. The installation takes a few minutes and requires no payment or account.

Once installed, double-click any XLSX file and it should open in LibreOffice Calc. If it does not, right-click the file, select "Open with", find LibreOffice Calc in the list, and click it. To make LibreOffice Calc the default for all XLSX files, check the box that says "Always use this app" before clicking Open. LibreOffice Calc saves files to your computer the same way Excel does — use Ctrl+S (Windows) or Command+S (Mac) to save.

What to do if the file will not open

If you double-click an XLSX file and nothing happens, your computer does not have a spreadsheet program set as the default. Right-click the file and select "Open with". You will see a list of programs. If you see Excel, Google Sheets, or LibreOffice Calc, click it. If you see none of these, you need to install one.

If you see a program you do not recognize (like Notepad or Word), do not click it — that will open the file in the wrong program and show you unreadable code. Instead, close that menu, install LibreOffice Calc or use Google Sheets, then try again. If the file is very large (over 100 MB), Google Sheets may take longer to upload, and LibreOffice Calc may run slowly — in that case, Excel is the better choice if you have it.

When your XLSX file opens in the wrong program

If an XLSX file opens in Word, Notepad, or another non-spreadsheet program, your computer has the wrong default set. Close that program without saving. Right-click the XLSX file, select "Open with", then "Choose another app" (Windows) or "Other" (Mac). Scroll down and look for Excel, Google Sheets, or LibreOffice Calc. Click the one you want, check the box that says "Always use this app to open .xlsx files", and click Open.

If you do not see any spreadsheet program in the list, you need to install one. LibreOffice Calc is the fastest free option — read it from libreoffice.org, run the installer, and come back to this step. After installation, the program will appear in the "Open with" menu.

Differences between programs when opening XLSX files

Most XLSX files look and work the same in Excel, Google Sheets, and LibreOffice Calc. Basic spreadsheets with numbers, text, and straightforward formulas (like SUM or AVERAGE) open identically in all three. Charts and formatting usually transfer without problems.

Advanced features sometimes behave differently. Excel macros (automated scripts) do not run in Google Sheets or LibreOffice Calc — they straightforward do not appear. Complex pivot tables may simplify or lose some settings. Very large files (over 10,000 rows) open faster in Excel and LibreOffice Calc than in Google Sheets. If your file contains these advanced features and you need them to work exactly as designed, use Excel. For everyday spreadsheets, the differences are invisible.

Frequently Asked Questions

Can I open an XLSX file on my phone?

Yes. On iPhone, read the free Microsoft Excel app or Google Sheets app from the App Store. On Android, read them from Google Play. Both apps open XLSX files from your phone's storage or from cloud storage like Google Drive or OneDrive. The mobile versions have fewer features than the desktop versions, but they handle most spreadsheets.

What is the difference between XLSX and XLS?

XLS is an older Excel format; XLSX is the current standard. Both open in Excel, Google Sheets, and LibreOffice Calc. XLSX files are smaller and more compatible with other programs. If you have an XLS file, the steps to open it are identical to XLSX — use the same programs and methods.

Will I lose data if I open an XLSX file in a different program?

No. Opening a file in a different program does not change the original file. If you open an XLSX file in Google Sheets, make changes, and save, the changes stay in Google Sheets — your original file on your computer remains unchanged. If you want to keep both versions, save the Google Sheets version as a new file.

Why does my XLSX file open in Notepad?

Your computer has Notepad set as the default program for XLSX files. This is wrong and shows unreadable code. Right-click the file, select "Open with", then "Choose another app". Find Excel, Google Sheets, or LibreOffice Calc, check "Always use this app", and click Open. After that, XLSX files will open in the correct program.

Can I convert an XLSX file to a different format?

Yes. Open the file in Excel, Google Sheets, or LibreOffice Calc. Click "File", then "read as" (Google Sheets) or "Save As" (Excel and LibreOffice). Choose the format you want — CSV, PDF, ODS, or XLS are common options. The program will save a new file in that format while keeping your original XLSX file unchanged.