What is .xlsx?
.xlsx is the default file format for Microsoft Excel spreadsheets created in Excel 2007 and later. It is an open XML-based format that stores data in worksheets, cells, rows, and columns, supporting formulas, charts, and complex formatting.
This quick guide explains when to use .xlsx files, how to open them on any device, and how to share them instantly with FileXhost.
When to use .xlsx files
- You need to perform calculations, data analysis, or create charts.
- You are sharing structured data that requires formatting (colors, borders).
- You need multiple sheets (tabs) in a single file.
- You are working with financial models or inventory lists.
How to open .xlsx files
XLSX files open natively in Microsoft Excel, Google Sheets, Apple Numbers, and LibreOffice Calc. With FileXhost, you can upload .xlsx files to view them directly in your browser as interactive, searchable tables without needing any software.
Algorithm details
Like .docx, the .xlsx format conforms to the Office Open XML standard. It is a zipped archive of XML files. This structure allows for smaller file sizes and better data recovery than the older binary .xls format. It separates data (values) from formatting and formulas.
Browser & platform support
- Desktop: Not natively supported by browsers for direct rendering, but FileXhost provides a built-in high-performance viewer.
- Mobile: Supported via apps like Excel, Google Sheets, or system viewers.
- OS: Native support on Windows and macOS via office suites.
Format comparison
| Feature | Details |
|---|---|
| Structure | Organized into cells, rows, and columns across multiple sheets. |
| Capabilities | Supports formulas, functions, charts, macros (in .xlsm), and rich formatting. |
| Size | Compact due to ZIP compression, unlike uncompressed CSVs. |
| Compatibility | Widely supported by all spreadsheet software and data tools. |
How to create xlsx files
- Spreadsheet Software: Microsoft Excel, Google Sheets, LibreOffice Calc.
- Data Tools: Python (pandas), R, SQL exports.
- Converters: CSV to XLSX tools.
How to convert xlsx files
- FileXhost: Upload to view as an interactive web table.
- Excel/Google Sheets: Save as CSV, PDF, or HTML.
- Online Tools: CloudConvert, Zamzar.
Advantages & disadvantages
Advantages
- Industry standard for data analysis
- Supports complex formulas and visualizations
- Multiple worksheets in one file
- Smaller file size than legacy .xls
- Rich formatting options
Disadvantages
- Requires specialized software to edit (unlike CSV)
- Can be complex to parse programmatically compared to CSV
- Version compatibility issues with very old Excel versions
Tools & software
Viewers
FileXhost (Web), Microsoft Excel Viewer, Google Sheets
Editors
Microsoft Excel, Google Sheets, LibreOffice Calc, Apple Numbers
Converters
FileXhost, CloudConvert, Python (pandas)
Libraries
SheetJS (JavaScript), pandas (Python), openpyxl (Python)
Frequently asked questions
What is the difference between XLSX and CSV?
CSV is a plain text format that stores raw data (values only) separated by commas. XLSX is a rich spreadsheet format that supports formulas, formatting, charts, and multiple sheets. Use CSV for data exchange, XLSX for analysis and presentation.
Can I open XLSX files without Excel?
Yes! You can use free tools like Google Sheets, LibreOffice, or upload it to FileXhost to view it instantly in your browser.
Are XLSX files safe?
Standard .xlsx files cannot contain macros (VBA code), making them safer than .xlsm or older .xls files which could host viruses.
Why is my XLSX file corrupted?
This can happen if the file download was interrupted or if it was saved incorrectly by a third-party tool. Try opening it in 'Safe Mode' in Excel or using a repair tool.
Technical specs
- File type
- Spreadsheet
- Extension
- .xlsx
- MIME type
- application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
- Compression
- Lossless
- Max file size on FileXhost
- Up to 25 MB per file on the free plan and up to 1 GB on Pro FileXhost accounts.
Share .xlsx files instantly
Upload your .xlsx file to FileXhost to get a clean, shareable URL in seconds. View the file in a modern browser, protect access with optional settings, and let others download it without any confusing ads or cluttered file pages.
Upload .xlsx file