Convert XLS to XLSX
Upgrade legacy Excel .xls workbooks to modern XLSX format.
Free XLS to XLSX converter
AnyConv365 helps you convert XLS files to XLSX without installing software. Open this page, choose your file, and download the result.
Common workflows include CSV ↔ spreadsheet exchanges for Excel, Sheets, or data pipelines without opening a desktop app.
How it works
Is XLS to XLSX conversion free?
Yes. AnyConv365 lets you convert XLS to XLSX online for free with no account required.
Will my file quality be preserved?
We aim for the best practical fidelity for each pair. Preview the download before sharing when quality is critical.
Do you store my files?
Server-side source files are deleted immediately after a successful conversion. If conversion fails, the source file is retained for up to one hour for error diagnosis and then deleted automatically.
Are formulas preserved?
CSV exports values, not live formulas. Keep an XLSX/ODS copy when you still need calculations.
Will macros survive XLS to XLSX?
Data and typical formatting convert, but legacy macros may be stripped or need rework in Excel.
Where can I learn more about this conversion?
See our guide: XLSM to XLSX Conversion Guide. It covers when to convert, common pitfalls, and related formats.
Related conversions
Related guides
- XLSM to XLSX Conversion Guide
Use this guide for keeping workbook data and formulas editable in an XLSX copy without macros. The steps below cover conversion and the checks worth making.
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