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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 plausibly 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. Not every step was tested on every OS version.
  • 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: external links should point to vendors, standards bodies, or other primary references where possible; not every detail is individually sourced.
  • Limits: this is clarity and safety-messaging QA, not a guarantee that every statement is exhaustive or that every binary you download is harmless. Pages without “Reviewed by” have not been through this editorial pass yet.

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.

Convert .XLSX files in your browser

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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.

Recommended software: Microsoft Excel · LibreOffice Calc (free) · Excel for the web (free with a Microsoft account)

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.

Recommended software: Numbers (built in) · Microsoft Excel · LibreOffice Calc (free)

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.

Recommended software: LibreOffice Calc (free) · OnlyOffice Desktop Editors (free)

Full Linux guide

iOS

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

Recommended software: Numbers (free) · Microsoft Excel (free for viewing) · Google Sheets

Full iOS guide

Android

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

Recommended software: Google Sheets · Microsoft Excel (free for viewing)

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.

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
  • "We found a problem with some content in file.xlsx. Do you want us to try to recover as much as we can?"
  • "Excel cannot open the file because the file format or file extension is not valid"

Fix steps

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

Repair a damaged .XLSX file

If the file opens with errors or not at all, a dedicated repair tool can often rebuild it. Work on a copy and keep the original file untouched.

Wondershare Repairit (Files and Photos)

Repairs damaged Word, Excel, PowerPoint, PDF and ZIP files as well as corrupt photos.

We may earn a commission when you use affiliate links. This supports our free file extension guides.

Recover a deleted or lost .XLSX file

If the file was deleted by mistake or the drive was formatted, data recovery software may be able to get it back. Stop writing to that drive right away, because new data can overwrite what you want to recover.

MiniTool Power Data Recovery

Windows software that recovers deleted or lost files from PCs and external drives such as HDDs, SSDs, USB drives and memory cards, after deletion, formatting or a crash.

Wondershare Recoverit

Windows and Mac software that recovers deleted or lost files from computers and external drives such as HDDs, SSDs, USB drives and SD cards.

We may earn a commission when you use affiliate links. This supports our free file extension guides.

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.

"We found a problem with some content in file.xlsx. Do you want us to try to recover as much as we can?"

Excel shows this when parts of the workbook, such as a sheet, formula or style, are damaged or created by a tool that wrote invalid XML.

  1. Click "Yes" and save the recovered workbook under a new name; Excel lists what it repaired.
  2. Alternatively open it via File → Open → Browse and use "Open and Repair".
  3. Try LibreOffice Calc or Excel for the web, which are sometimes more tolerant.
  4. If the file came from an export or script, export it again, for example as CSV.

"Excel cannot open the file because the file format or file extension is not valid"

The extension says .xlsx, but the content is something else, such as a renamed .xls, CSV or HTML export, or the file is corrupt.

  1. Make a copy and try changing the extension to .xls or .csv, then open it again.
  2. Open the file in a text editor: if you see readable text or HTML tags it is not a real .xlsx file.
  3. Use our header analyzer to check what the file really is.

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.

Similar file extensions

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