How do I open an .xlsx file without Excel?

LibreOffice Calc and ONLYOFFICE open XLSX free on any desktop platform, and Google Sheets does it in a browser. On macOS, Numbers is already installed and imports the format.

Why does Excel say the file format does not match the extension?

The file is not really an XLSX. It is typically a CSV or an HTML table that was renamed. Opening it anyway usually works, and re-saving it as a real workbook fixes the warning permanently.

File extensions

How to open a .xlsx file

Excel workbook · Spreadsheet

An .xlsx file is an Excel workbook. LibreOffice Calc, ONLYOFFICE and Google Sheets all open it free. Like .docx it is a ZIP inside, so a corrupt one can often be recovered.

What a .xlsx file actually is

XLSX replaced the old binary .xls in Office 2007. It is an Office Open XML package: a ZIP containing XML for each worksheet, plus shared strings, styles and any embedded charts.

The format also lifted the old limits, going from 65,536 rows to just over a million, which is why exports from databases and analytics tools now arrive as XLSX by default.

Why it will not open

Usually no spreadsheet application is installed. The other common case is Excel refusing to open a file it says is corrupt or in a different format than the extension suggests, which normally means it is really a CSV or HTML table someone renamed.

Renaming it to an extension you can open will not help: changing the extension does not convert the file, it only changes what Windows tries to open it with.

Step by step

Windows

01Install LibreOffice or ONLYOFFICE, both free, or upload the file to Google Sheets.
02If Excel warns the file format does not match the extension, it is probably a CSV or HTML table renamed to .xlsx. Open it anyway when prompted and it will usually display correctly.
03For a genuinely corrupt workbook, use File, Open, then the arrow next to Open, and choose "Open and Repair".
04As a last resort, rename a copy to .zip and extract xl/worksheets to recover the raw cell data as XML.

macOS

01Numbers opens .xlsx and can export back to Excel format.
02LibreOffice Calc preserves formulas and formatting more faithfully than Numbers for complex workbooks.

What usually goes wrong

Macros do not survive in .xlsx

The .xlsx format deliberately cannot store macros; those need .xlsm. If a workbook lost its automation after being saved, it was almost certainly saved to the wrong format.

Programs that open .xlsx

Our pick, in order. Every one links to the publisher's official download URL and the SHA-256 hash of the installer. Once you have downloaded it, you can check the file against our index before you run it.

If you end up downloading one of these from somewhere other than the publisher, what you can and cannot verify about that is worth two minutes.

Common questions

How do I open an .xlsx file without Excel?: LibreOffice Calc and ONLYOFFICE open XLSX free on any desktop platform, and Google Sheets does it in a browser. On macOS, Numbers is already installed and imports the format.
Why does Excel say the file format does not match the extension?: The file is not really an XLSX. It is typically a CSV or an HTML table that was renamed. Opening it anyway usually works, and re-saving it as a real workbook fixes the warning permanently.