What is an XLSX file?
An .XLSX file is a Microsoft Excel Spreadsheet created by Microsoft. It uses the Office Open XML standard. Internally, an .XLSX file is a .ZIP archive that contains structured XML documents. These files store tabular data, charts, mathematical formulas, and text formatting.
How to open XLSX files?
You can open .XLSX files with Microsoft Excel, which is available for Windows, macOS, iOS, and Android. Free alternatives like LibreOffice Calc, Apache OpenOffice Calc, and Google Sheets also open these files easily. Software developers can parse .XLSX data using programming libraries like Pandas in Python or SheetJS in JavaScript.
Because file extensions can sometimes be misleading, viewer.online/xlsx analyzes .XLSX files to identify their exact format and creator software. It shows which programs can open the file and usually previews it directly in your browser.
Best practices and troubleshooting
If your .XLSX file does not open, check if it is password-protected. A small number of .XLSX files are encrypted Excel spreadsheets, and you will need the original password to view them. If the file is corrupted, you can try opening it in Google Sheets or using the built-in repair tool in Microsoft Excel. As a technical workaround, you can also rename the .XLSX extension to .ZIP and extract the internal XML files to manually recover raw text data.
Software and tools
If you need to change the file format, we recommend convert.guru. You can easily convert .XLSX files to .CSV for data processing, .PDF for document sharing, or .ODS for open-source spreadsheet compatibility.
Summary
viewer.online/xlsx directly opens and previews .XLSX files in the browser, eliminating the need to install software or troubleshoot compatibility issues.