XLS to XLSX
Convert XLS files to XLSX in seconds, for free. Nothing to install.
Files are deleted from the server automatically after 1 h.
Why convert XLS to XLSX?
- XLSX is the modern Office format: smaller files and full compatibility with Microsoft 365.
- XLSX is one of the most widely supported formats — it opens almost anywhere.
You don't need to install any software to convert XLS to XLSX. Upload your file, choose XLSX and download the result a few seconds later. The conversion runs on our servers and your file is deleted automatically after 1 h.
XLS vs XLSX: comparison
| Feature | XLSMicrosoft Excel 97–2003 Workbook | XLSXMicrosoft Excel Open XML Workbook |
|---|---|---|
| Developer | Microsoft | Microsoft |
| Released | 1997 | 2007 |
| Type | spreadsheet | spreadsheet |
| Editable content | ✓ yes | ✓ yes |
| Opens with | Microsoft Excel, LibreOffice Calc, Google Sheets | Microsoft Excel, LibreOffice Calc, Google Sheets |
Tip: CSV files are saved as UTF-8, so non-Latin characters display correctly.
How it works
- Choose or drop your XLS file.
- Pick XLSX as the output format.
- Click “Convert” and download your file.
XLS to XLSX: questions and answers
Will quality be lost when converting XLS to XLSX?
Text, tables and images are kept. Very complex layouts or rare fonts may shift slightly.
How long does XLS to XLSX conversion take?
Usually 1–10 seconds. Several files are processed in parallel.
What is the maximum XLS file size?
Up to 50 MB per file and up to 20 files at once — for free.
Can I convert XLS to XLSX on my phone?
Yes. TezConvert works in any browser on Android and iPhone — no app needed.
How do I open a XLSX file?
XLSX files open in: Microsoft Excel, LibreOffice Calc, Google Sheets.
Are my files safe?
Files are used only for the conversion, never shown to anyone, and deleted automatically after 1 h. The original is deleted right after conversion.
⇄ Need the opposite? Convert XLSX to XLS →