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.XLSX file extension

To open .XLSX files on Windows, open with Microsoft Excel by double-clicking the file.

XLSX files are spreadsheet workbooks that can be opened with Microsoft Excel, Google Sheets, or LibreOffice Calc.

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Last updated: March 19, 2026 · Reviewed by Julian Stricker

What “reviewed” means on this page
  • Format fit: whether the “what is this file?” description matches common real-world use of the extension, including category, typical MIME types, and aliases.
  • Opening paths: whether Windows / macOS / Linux steps read plausibly for current OS dialogs and default apps; we remove fantasy menus and unsafe shortcuts.
  • Security framing: whether risk notes match the extension class (for example executables vs plain data) and whether affiliate wording does not contradict the security section.
  • Sources and further reading: whether external links point to vendors, standards bodies, or other primary references where possible; we avoid inventing details we cannot ground.
  • Limits: this is clarity and safety-messaging QA, not a guarantee that every statement is exhaustive or that every binary you download is harmless.

Full methodology in the Imprint — The Imprint also states where AI is used and what that does—and does not—replace.

Open on your device

Choose your operating system for a dedicated step-by-step opening guide.

How to open .XLSX files

Use these platform-specific instructions to open .XLSX files safely.

Windows

  1. Open with Microsoft Excel by double-clicking the file.
  2. If issues arise, right-click the file and select 'Open with' to choose Excel.
Full Windows guide

Mac

  1. Double-click to open in Excel or drag the file into Numbers.
  2. Check formulas and dates after opening in Numbers.
Full Mac guide

Linux

  1. Open with LibreOffice Calc by right-clicking and selecting 'Open with'.
  2. Ensure locale settings match for accurate data representation.
Full Linux guide

iOS

  1. Open in Excel mobile from the Files app or use Numbers for basic viewing.
Full iOS guide

Android

  1. Use the Excel app or Google Sheets to open directly from your device.
Full Android guide

Security notes

  • Be cautious with external links and data connections.
  • Avoid enabling macros in files from unknown sources.
  • Use protected view for files received via email.

If you did not expect this file

This extension is usually plain data, text, or structured content—not a program by itself. The practical risk is social engineering (a scam attachment or misleading filename). For trusted senders you rarely need heavy-handed antivirus wording; use these tools when you want an extra check on unexpected downloads.

Avast

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Norton

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Can't open this file?

These are the most common causes and fixes when .XLSX files fail to open.

Common reasons

  • Formulas return errors
  • File won't open

Fix steps

  1. Verify the locale settings in your application.
  2. Re-enter the formulas manually if necessary.

OS-specific troubleshooting

Convert .XLSX to other formats

Use conversion tools to change .XLSX files into formats your software supports.

What is a .XLSX file?

XLSX is the default format for Excel workbooks, utilizing the Office Open XML standard. It stores data in a compressed ZIP format containing XML files for worksheets and other components.

Background

Introduced with Microsoft Office 2007, the XLSX format replaced the older XLS format, providing better data management and reduced file sizes through XML-based storage. XLSX files are commonly used in business, education, and personal finance for tasks such as budgeting, data analysis, and reporting. The format supports advanced features like pivot tables, charts, and complex formulas, making it a versatile tool for data manipulation. Due to its open XML structure, XLSX files can be accessed and manipulated by a variety of software applications beyond Microsoft Excel, enhancing cross-platform compatibility.

Common MIME types: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

Further reading

Authoritative resources for more details on the .XLSX format.

Common .XLSX issues

Formulas return errors

This can occur due to different locale settings or unsupported functions.

  1. Verify the locale settings in your application.
  2. Re-enter the formulas manually if necessary.

File won't open

This might happen if the file is corrupted or the application is outdated.

  1. Try opening the file in another application like Google Sheets.
  2. Check for updates for your spreadsheet software.

FAQ

Why can't I edit the file?

The file might be in read-only mode; check the file properties or permissions.

Can I convert XLSX to PDF?

Yes, most spreadsheet applications, including Excel, allow you to export or save as PDF.

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