XLS to XLSX — Upgrade Legacy Excel Files

The XLS format was replaced by XLSX in 2007, but many organizations still have legacy spreadsheets in the old format. The MyPDF XLS to XLSX converter modernizes your files instantly.

How to Convert XLS to XLSX

1. Upload your XLS file using the file picker or drag-and-drop.
2. Configure any conversion preferences for the output file.
3. Download your modern XLSX file, compatible with all current spreadsheet applications.

XLS vs XLSX

Feature	XLS	XLSX
Format	Binary (BIFF)	ZIP-compressed XML
Max rows	65,536	1,048,576
Max columns	256	16,384
File size	Larger	Significantly smaller
Cloud compatibility	Limited	Full (Google Sheets, etc.)

Practical Tips

• Free up storage. XLSX files are typically 50-75% smaller than their XLS equivalents due to ZIP compression, saving significant disk space for large archives.
• Unlock modern formulas. XLSX supports newer Excel functions like XLOOKUP, dynamic arrays, and Power Query that are unavailable in XLS.
• Preserve your data. XLS has a 65K row limit. If your data approaches this limit, converting to XLSX prevents accidental data loss.

Will my formulas still work after conversion?

Yes. Standard Excel formulas transfer cleanly from XLS to XLSX. VBA macros require saving as XLSM (macro-enabled) to remain functional.

Can I convert multiple XLS files at once?

MyPDF supports batch uploads, letting you convert an entire folder of legacy spreadsheets in one session.

Do I need Microsoft Excel installed?

No. MyPDF converts your files entirely online without requiring Excel or any other desktop software.

Related Tools

• XLS to PDF — Convert Excel spreadsheets directly to PDF.
• XLSX to CSV — Export spreadsheet data as CSV.
• ODS to XLSX — Convert LibreOffice Calc files to Excel.
• XLSX to ODS — Convert Excel files to LibreOffice format.